Saturnalia is an ancient Roman festival and holiday in honour of the god Saturn, held on 17 December of the Julian calendar and later expanded with festivities through 19 December. By the 1st century B.C., the celebration had been extended through 23 December, for a total of seven days of festivities. The holiday was celebrated with a sacrifice at the Temple of Saturn, in the Roman Forum, and a public banquet, followed by private gift-giving, continual partying, and a carnival atmosphere that overturned Roman social norms: gambling was permitted, and masters provided table service for their slaves as it was seen as a time of liberty for both slaves and freedmen alike. A common custom was the election of a "King of the Saturnalia", who gave orders to people, which were followed and presided over the merrymaking. The gifts exchanged were usually gag gifts or small figurines made of wax or pottery known as sigillaria. The poet Catullus called it "the best of days".

Festivals in ancient Rome were a very important part in Roman religious life during both the Republican and Imperial eras, and one of the primary features of the Roman calendar. Feriae were either public (publicae) or private (privatae). State holidays were celebrated by the Roman people and received public funding. Games (ludi), such as the Ludi Apollinares, were not technically feriae, but the days on which they were celebrated were dies festi, holidays in the modern sense of days off work. Although feriae were paid for by the state, ludi were often funded by wealthy individuals. Feriae privatae were holidays celebrated in honor of private individuals or by families. This article deals only with public holidays, including rites celebrated by the state priests of Rome at temples, as well as celebrations by neighborhoods, families, and friends held simultaneously throughout Rome.