These are the people who run things. They keep society moving smoothly, if they're good at what they do, and can bring society to a crunching halt, if they're not. Rife for corruption, government officials can play a significant role in many campaigns.

bailiff - the man who makes arrests and executions. Bailiff was not primarily used for the office of policeman. Etymologically, bailiffs were those in charge of the bailey - in effect, manager of the craftsmen and servants in a castle or manor house.
catchpole - literally 'chicken catcher', one who finds and brings in debtors.
chancellor - a secretary to a noble or royal
constable - the warden of a town or castle
diplomat - the person who negotiates with foreign nations
emperor - the ruler of an empire
exchequer - the man responsible for the king's revenue
hayward - an officer in charge of fences and hedges
herald - had two responsibilities: a man in charge of making pronouncements and proclamations, and one who is an expert in the field of heraldry (the various insignias used by the rich to identify themselves.) These two responsibilities were one in the same. Medieval Europeans wouldn't have thought it possible to separate them; much less would they have considered them separate roles.
jailer - the man responsible for a jail: he keeps the criminals from getting out
judge - a man who is responsible for deciding questions brought to court
king - ruler of a kingdom
knight
lady
liner - an officer in charge of tracing property boundaries in the city master of the revels - official in charge of court entertainment, and later of the theaters [note: the first Master of the Revels was not appointed until Henry VII in the 15th century]
nobleman
prince
pursuivant - officer of arms, ranks below herald, similar duties
reeve - church warden. Note that the word 'reeve' applies to much more than the Church. Reeves usually came out to be combination administrators and business managers of estates, towns and small territories (i.e. shires) - something like a chief bailiff.
sherrif
summoner - officer of the court who serves subpoenas (see also religious version)
watchman
woodward - the keeper of a forest

Military Occupations

Who keeps the country safe from encroaching enemies and wild monsters? Why, the military, of course. These brave men - and sometimes women train against the possibility that they'll have to protect their country with their lives.

Arbalestier - one who fires an arbalest (a type of metal crossbow)
archer - one who shoots arrows
bowman
camp follower - people following an army, making money off of the soldiers
cannoneer
crossbowman
drummer
engineer
guardsman
halberdier
Knifeman - one skilled with a knife; specifically, a soldier trained to disembowel horses
mercenary
pikeman
pioneer - an early term for military engineer
sapper - specialist in field fortifications
scout
siege engineer
sergeant
sergeant-at-arms
spearman
spy

Criminal Occupations

Wherever there is society, there are criminals. These occupations include only the so-called "professional criminal": it ignores those people who are corrupt at every level of society who has a legal "front", from kings to beggars.

boothaler - marauder, plunderer
burglar - one who breaks into, and steals things from, other people's houses. (If you break into and steal stuff from your own house, you're just a nut.)
diver - fig. a pickpocket
fence - one who trades in stolen goods
footpad - one who robs pedestrians
outlaw - a man wanted by the law
pickpocket - one who picks pockets
poacher - one who illegally kills animals, usually on somebody else's land
silk-snatcher - one who steals bonnets
stewsman - probably a brothel keeper - "since the words stew and stewholder both mean a bawd, I'm guessing that a stewsman would be a brothel-keeper as well. Whether bawdry counts as a criminal activity varies at different times and places."
thimblerigger - a professional sharper who runs a thimblerig (a game in which a pea is ostensibly hidden under a thimble and players guess which thimble it is under)

Religious Occupations

If Government officials run the affairs of earthly beings, then those occupied with religious pursuits mediate between earth and the gods.

Priests are relatively common in role playing games. These men and women are the people behind the church: not typically "adventuring priests", but vitally important to the church nonetheless.

abbess - superior of a convent
abbot - superior of a monastery
almoner - a distributer of money and food to the poor archbishop
beadle - church official -- ushers preserves order at sermons
beguine - member of certain Netherland lay sisterhoods
bishop
canon - a prebend attached to a cathedral (the definition is somewhat wider, but that's the most common usage)
cantor - a choir leader in churches, the man who sings hymns and leads the congregation in prayer in a synagogue
cardinal
chantry priest - a priest employed to say prayers for the dead; often taught on the side (thus so-called chantry schools)
chaplain
clark - see clerk
clerk - a priest
curate - priest in charge of a church
friar - a wandering monk, especially a Franciscan
metropolitan - a bishop in charge of other bishops; an archbishop
monk
nun
ostiary - a church's doorkeeper
palmer - a pilgrim who's been to the Holy Land
pardoner - seller of indulgences
parish priest
pilgrim -
pope
priest
primate - head of the Church in a country or region (i.e. the Archbishop of Canterbury was Primate of England)
sacristan - a person in charge of the relics and religious items of a church
sexton - minor church officer - rings bells, digs graves
summoner - officer who brings people to episcopal courts (see also government version)

Merchants

In a society based on trade - either with hard currency or barter, there are always those who spend their lives in the pursuit of selling things to others.

Note that most craftsmen also sell the results of their labor, farmers typically must sell their crops themselves, people in service trades often must hawk their own wares. This section does not include them. It includes only those people who spend their entire lives devoted to selling things, and nothing more.

acater - a provisioner (food)
alewife - a female alehouse keeper
apothecary - a preparer and merchant for drugs and medicines
banker
beer seller
boothman - one who sells grains
chapman - travelling merchant
collier - one who makes or sells charcoal (later coal) [can also fit under craftsmen]
colporteur - seller of religious books
costermonger - fruit seller
drover - one who drives sheep or cattle to market
eggler - an egg-merchant
fishmonger
fruiterer - a seller of fresh fruit
fruitier - fruitseller
fueller - one who sells charcoal, wood, or other fuels
glass seller
greengrocer - seller of vegetables and fruits
grocer
harberdasher - seller of men's clothing
hay merchant
hetheleder - one who sells heather as fuel
innkeeper
ironmonger - one who sells things made of iron
lighterman - one who ferries goods from ship to shore on a small boat
linen-draper - one who deals in linens, calicos, etc.
mercer - a dealer in expensive clothing (silk, etc.)
merchant
milkmaid - a female servant who milks cows
oil merchant
old-clothes dealer
oynter - an oil-merchant
peddler
pie seller
plumer - a dealer in feathers
poulter - seller of poultry
shrimper - one who catches shrimp
skinner - a dealer in furs and skins (essentially, the same thing as a furrier)
spice merchant
spicer - grocer or dealer in spices
stationer - seller of books, etc.; also, a copyist
taverner - innkeeper
thresher - one who thrashes grain, separating it from straw
unguentary - one who sells unguents
waferer - confectioner (a dealer in 'wafers', a kind of cake)
waterseller
weirkeeper - a keeper of fish traps
wine seller
wood seller
woodmonger - a seller of fuel wood
wool stapler - one who buys and sells wool wholesale

Artists/Entertainers

In any society, there is the need for spare time. And what did people do before television? Well, they mostly sang songs, told stories, and danced. From this, some professional entertainers developed.

Also included in this section are artists: those who devote their lives to creating works of beauty and expressiveness. There is enormous overlap between artists and entertainers... I won't get into the argument of whether art should be used to entertain or express the artist's true feelings. That's beyond my scope here, certainly.

bard - a Welsh minstrel
barker - one who advertises at the entrance to a show
bear-ward - the owner of a performing bear
fiddler - this is an unfair translation, "geiger" is applied to any player of bowed and stringed instruments
fool
fresco painter
glasspainter
harper
illuminator
jester
limner - illuminator of books
lutenist - a lute player
minnesinger - a German minstrel who specialized in love songs
mummer - actor, specifically the predecessors to mimes
musician
nakerer - a player of the naker a small kettle drum
organist
painter - portraits and landscapes
piper
player
playwright
poet
sculptor
singer
troubadour - most properly a minstrel from the southern part of France (though it can be used of any minstrel who specializes in romances).
tumbler
writer

Farming and Workers with Flora and Fauna

Ah -- the farmers. Without them, we'd starve. Wresting sustenence from the very earth itself. There's a large number of occupations associated with farming: you need people to watch the animals, work the fields. In fact, probably most people in a medieval society were farmers.

Also included are hunters and gatherers: those who travel into nature and grab things to eat, as well as all those who work with animals.

ackerman(acreman) - an oxherder
falconer - breeds, trains, hunts with falcons
farmer
fewterer - one who keeps the hunting dogs
fisherman
forester - game warden or forest ranger
fowler - one who hunts for wildfowl
gamekeeper
goatherd - one who looks after a herd of goats
hawker - breeds, trains, hunts with hawks
hayward - a tender of hedges
horse trainer
hunter
huntsman
master of hounds
molecatcher
ostler - cares for horses
oyster raker - worker on an oyster fishing boat
oysterer - one who catches oysters
parker - caretaker of a park
plowman
rat catcher
reaper
sheepshearer
shepherd - one who looks after a herd of sheep
swineherd - one who looks after a herd of swine (sometimes pigherd)
thresher
tillerman
trapper
woolcomber
woolman - sorts wool into differing grades

Scholars

They may have called it the dark ages for lack of scientific output, but there were still people interested in the world around them, willing to poke and prod it until something broke.

alchemist - a medieval chemist
astrologer
astronomer
bearleader - a travelling tutor (a silly name) - related to the figurative use of the word bear to describe a boor.
dean
librarian
mathematician
philosopher
professor
scholar
scrivener - scribe
tutor
theologian - a scholar specializing in the study of God and doctorine

Sailors

The lure of the sea, the crash of the waves: a boat-filled life was the norm for a great many medieval people. Some sailed on rivers, some on the ocean. Exciting and dangerous trade missions with far-off empires, exploring strange new places, and always coming back home to tell exciting stories in the local tavern.

bargeman
boatman
canaller - canal boat worker
ferryman
hobbler - boat tower on a river or canal
lighter man - worker on a flat-bottomed boat
mariner
navigator
pilot
sailor
sea captain
ship's captain
shipchandler - ship provisioner
waterman - riverboat sailor

Regular Folks

One of the problems with coming up with a list of Medieval Occupations is that lots of people in a feudal economy didn't have occupations at all. They were just tenants of other folks. Also, there are in any society, a large number of homeless and impoverished.

This section deals with people like that.

begger
buffoon - publically amusing person
clown - a peasant
crofter - tenant of a small piece of land
dwarf
franklin - a freeholder
gardner - one who gardens
hermit
housewife
landlord
palmer - one who had been, or pretended to have been, to the Holy Land
peasant
pilgrim
spinster
tenter - an unskilled workman's assistant

Craftsmen

Game worlds typically have armorers and blacksmiths, but then it breaks down, and everything else is available from the marketplace or the "general store". Add a bit of spice to a campaign by having the player's harness become damaged, and have to deal with the local harness maker - who is also the town shoemaker and his loud wife!

Most of the occupations on this list are craftsmen and service occupations. Because of this, I have seperated out the most common craftsmen from the bulk of the list, so that the gentle reader can make sense of it. The list of common occupations was derived from the tax list for Paris in 1292, from the book Life in a Medieval City, by Francis and Joseph Gies.

shoemaker - one who makes and repairs shoes
furrier - one who makes and repairs goods made of furs - esp. clothes
tailor - one who makes and repairs clothing
jeweler - maker of jewelry
pastrycook - baker specializing in pastries
mason - bricklayer
carpenter - one who constructs things from wood
weaver - weaver of cloth
chandler - one who makes candles, also grocer. Often associated with ships (see shipchandler)
cooper - one who makes and repairs barrels and tubs
baker - one who makes bread and other baked goods
scabbard maker - maker of scabbards
hatmaker - maker of hats
saddler - maker of saddles
chicken butcher - butcher of chickens purse maker - maker of purses
meat butcher - butcher of all sorts of meats, esp beef
buckle maker - maker of buckles
blacksmith - one who works with iron to form metal implements: esp farm tools.
roofer - one who makes and repairs roofs
locksmith - one who makes and repairs locks
ropemaker - maker of rope
tanner - preparer of leather
rugmaker - maker of rugs
harness maker - maker of harnesses
bleacher
cutler - one who makes and repairs cutlery
glover - a glovemaker

Less common craftsmen - sorted alphabetically

accoutrement maker - makes military accessories
alabasterer - worker in alabaster
architect - a designer of buildings and other constructions
arkwright - a maker of "arks" -- wooden chests or coffers
armorer
balancemaker
basketmaker
beekeeper - also known as apiarist
beerbrewer
bellfounder
bellmaker - these are the little bells that go on sleighs and clothing, as opposed to the large civic bells cast by the bellfounder
besom maker - one who makes brooms (known as besoms in the middle ages: 'broom' was the name of the plant use to make them)
billier - axe-maker
blockcutter - for block printing
bodger - itinerant wood turners
bonecarver
bookbinder
bookprinter
bottelier - maker of leather bottles
bowyer - maker of bows
brazier - makes brassware
brewer
bricker - brick baker, not mason
bricker - brick-maker
bricklayer
broderer - embroiderer
bronzefounder
broom-dasher - maker of brooms
brushbinder
builder
buttonmaker
cabinetmaker
campaner - maker of large bells (church-bells, for example)
canvasser - canvas-maker
carder - one who cards wool (combs out wool in preparation for spinning it)
cardmaker
cartwright
chainmaker
charcoalburner
cheesemaker
clockmaker
clothier
cobbler - shoe maker
coiner
combmaker
compasssmith
confectioner
coppersmith, redsmith - a worker in copper and brass
cordwainer - worker in fine leather
corsetier - maker of corsets and other undergarments
currier - one who cures leather
delver - ditchdigger
diamantaire - diamond-cutter (actually, diamond-cutting wasn't discovered until after the Middle Ages, but once it was diamantaires usually had their own guilds)
disher - a potter who makes dishes
draper - Originally, drapers were clothiers, though today the British use the word for a dry goods merchant.
drycooper
drywaller
dyer - one who dyes cloth
embroiderer - one who decorates fabric with stitched designs
engraver - for printing, not to decorate items
fabricshearer - trims the nap and makes pleats for customers
feltmaker
fewtrer - felt-maker
fletcher - maker of arrows
founder - foundryman
fuller - cloth worker who shrinks, beats, presses cloth
fuller - someone who cleans and thickens cloth by beating it
furniture maker
gemcutter
gilder - one who gilds (applies gold leaf to something)
girdler - leather worker who made girdles and belts, chiefly for the Army
girdler - belt-maker
glassblower - one who makes glass objects by blowing
glazier - maker of stained glass
goldbeater - one who makes gold foil
goldsmith - a worker in precious metals. In the Middle Ages, all people who worked in precious metals were called goldsmiths; the term silversmith is a much later word.
gravedigger
grinder - knife sharpener
gunsmith
gunstocker
hacker - hoe-maker
hatter - one who makes and repairs hats
horner - craftsman who works in horn -- spoons, combs, musical instruments
ivorist - an ivory-carver
joiner - skilled carpenter
knacker - harness-maker
knapper - a worker in flint
knifesmith
lacemaker
lampwright - maker of lamps and lanterns
lancier - a maker of lances
lanternmaker
lapidary - worker with precious stones -- usu. other than diamonds
latoner - worker in brass and latten (a brass-like alloy)
leadworker
lensgrinder
limner - someone who illuminates manuscripts
linen-armorer - one who makes cloth armor [same as a merchant taylor]
linener - a shirt maker [also, a linen-draper]
linenspinner
lorimer - maker of horse gear
lutemaker
luthier - a maker of stringed instruments (lutes, guitars, etc.)
mailer - enameller -- not a maker of armor
mailmaker
malemaker - a maker of leather trunks
mapmaker - also known as cartographer
marler - one who digs 'marl', a type of soil used as fertilizer.
marleywoman - a maker of marli, a type of fabric (gauze used for embroidery). Note that embroidery on this material is also known as marli.
master builder - chief architect
merchant taylor - tailors and "linen armourers"; they made the padded tunics soldiers would wear under metal armor
milliner - maker of womens' hats and clothing
miner
miniaturist - painter of miniatures (small paintings usually found on icons or in books)
minter, mintmaster, moneyer - one who mints coins
mirrorer - one who makes mirrors?
nailmaker
nedeller - maker of needles
netmaker
oilmaker
papermaker
parchmenter
parchmenter - a parchment-maker
pasteler - a pastry-maker
pattenmaker
pewterer
physician
pinmaker
plasterer
plattner - beat out sheets of metal
plumber - worker in lead
pointer - lace-maker
poleturner - maker of polearms (spears, pikes, halberds, etc.)
pot mender
potter
printer
purser - a purse-maker
quarryman
quilter - a quilt-maker
rectifier - one who distilled alcohol
reedmaker - a maker of flutes and other wind instruments
roper - maker of ropes, nets
rugweaver - one who makes rugs
sailmaker
saltboiler - makes salt by boiling water
salter - makes or deals in salt
sawyer - saws timbers to boards
scythesmith
seamstress
shingler - wooden roof tiler
shipwright - a ship builder
siever - a maker of sieves (a picture)
silkmaid, silkwoman - a woman who makes items out of silk.
silk-dresser, silk-maker, silk-mercer, silk-dyer, silk-carder - various individuals making silk articles.
silversmith
smelter - refines raw ore into pure metals
smith - blacksmith
spectaclesmaker
spooner - a spoon-maker
spurrer - maker of spurs
stonecarver
stonecutter
swordsmith
tallowchandler
tapestrymaker
tapicer - tapestry maker
tasseler - one who makes tassels
thacker, thatcher - one who covers roofs with thatch
thonger - maker of leather straps or laces
threadmaker
tile-burner - one who forms clay into tiles and bricks
tiler, tile-theeker, tyler - one who roofs with tile
tile maker - tile-maker
tinker
tinsmith
treen maker - one who makes various small wood items
turner - lathe worker (makes turned wooden objects, like chair legs)
typefounder
upholder - an upholsterer
vaginarius - scabbard-maker (pl. vaginarii)
vintner - a winemaker
waxchandler
webber - weaver
wheeler - maker of spinning wheels
wheelwright - a maker of wheels
wiredrawer - maker of gold and silver wire
woodcarver
woodcutter
woodturner

Service Occupations

There are many important positions in society for those who do not produce, but serve their fellow man. When they're done their job for the day, there are no new products, no changes in physical objects, but people are moved, jobs get done, and society keeps moving. These are the service workers.

Service workers can play an enormous role in your campaign. All the time, characters need to get their hair cut, have water fetched, or have something written down.

Common Service Occupations
maidservant
barber - one who cuts hair, also performed surgery and pulled teeth.
restaurateur - one who owns or runs a restaurant
water carrier
laundress - also known as lavendar
porter - one who carries burdens, or one who waits at doors.
doctor
bather - owner of a bath
copyist - one who copies books and documents -- not all of them can read

Less common service occupations

accomptant - an accountant
accoucheur - midwife
accoucheus - midwife
accountant - man who does financial bookkeeping
actuary - man who does financial bookkeeping, clerk
attendent
bagger
bailiff - the man who makes arrests and executions. Bailiff was not primarily used for the office of policeman. Etymologically, bailiffs were those in charge of the bailey - in effect, manager of the craftsmen and servants in a castle or manor house.
barrister - solicitor or lawyer
bath attendent
bather - owner of a bath
bodyservant
butler - one in charge of the buttery (where alcohol was kept)
carman - one who drives a vehicle for transporting goods
carter - one who drives carts
cartier
carver - the servant who cut the meat
ceiler - one who installs ceilings
cellarer - one in charge of the wine cellar
chamberlain - a private attendant who waits on his lord in his bedchamber
chimney sweep - one who cleans chimneys and smokestacks.
chirurgeon - surgeon
clouter - one who fixes things, a tinkerer
cook - one who cooks, especially food.
cowherd - one who looks after a herd of cows. A medieval cowboy, as it were.
currier - see tanner
dairymaid
dapifer - a servant who brings the meat to the table
dentist
ditcher - one who digs ditches
diver - one who dives for a living.
dog trainer
drayman - cart driver
dung carter
executioner
famulus - "a servant or attendant, esp. of a scholar or a magician" (Random House Dictionary of the English Language)
farrier - maker of tack, esp. horeshoes; also a horse-veteranarian
groom - one who takes care of the horses
harlot - vagabond, beggar, rogue, 14th century male servant, attendant or menial, and 15th century, loose woman
horseleech - veterinarian, farrier
hurdle maker - made 'wattle fences' for sheep
lawyer - a master of the law.
link boy - boy who will carry a torch to guide people through the night
link man - like a link boy, only older
maid - a female household servant. A maid is always female; the word literally means virgin.
marshal - a horse tender
midwife - humorously known as a babycatcher
miller - the person who turns grains into flour.
napier - the person who manages royal linens
nurse
panter - keeper of the pantry
paperer - needlemaking industry -- inserted needles into paper to prepare for selling
pavior - one who lays pavement
pavyler - put up pavilions/tents
pissprophet - doctors who would diagnose disease from a patient's urine, specifically from the sight, smell, and taste of the urine.
potboy - cleans out chamber pots
privycleaner
procurator - or proctor, this is a kind of legal agent or representative
prostitute - one who sells sex
quartermaster
ragpicker - sorts through leftover rags, find re-usable ones
raker - street sanitation worker
riveter - one who rivets (a rivet being a nail designed to secure metal to metal)
scullion - the bottom-rung servant in a household
seneschal - senior steward
solicitor - lawyer
sperviter - a keeper of sparrow-hawks
stainer - one who stains wood
stillroom maid
surgeon
tapster - one who draws ale, etc. at an inn; innkeeper/bartender/barmaid
teamster - one who drives a team of oxen or horses
trencherman - carver, trench-digger
userer - a moneylender, specifically a Jewish moneylender (the only people allowed to hold such a job in the Middle Ages)
wagoner - wagon or cart driver
waller - one who builds walls
wattler - made 'wattle fences' for sheep
weeper
wetnurse

Other

basinbeater - ? a maker of metal basins?
belter - ? maker of belts ?
fool for money - ?
gluttonous fool - ?
nailer - ? one who makes nails ?
rivener - ?
tentsman - ?
terrazo grinder/mosaic layer - ?
thimbler - ?