Fitzwilliam College is a constituent college of the University of Cambridge, England. The college has origins from 1869, with the foundation of the Non-Collegiate Students Board, a venture intended to offer academically excellent students of all backgrounds a chance to study at the university. The institution was originally based at Fitzwilliam Hall (later renamed Fitzwilliam House), opposite the Fitzwilliam Museum in south-west Cambridge. Having moved to its present site in the north of the city, Fitzwilliam attained collegiate status in 1966. Female undergraduates were first admitted in 1978, around the time most colleges were first admitting women.

Fitzwilliam is now home to around 500 undergraduates, 400 graduate students and 90 fellows. By overall student numbers, it was the seventh-largest college in Cambridge as of 2018/19. The college's boat club is Fitzwilliam College Boat Club.

Notable alumni of Fitzwilliam College include six Nobel laureates, a large number of prominent academics, public officials, businesspeople, clergy and athletes, three heads of state or government, one former UK Supreme Court Justice, and a significant number of political figures including a former Liberal Democrats leader, a former Chancellor of the Exchequer, and two former Commissioners of the Metropolitan Police.