A fabliau (French pronunciation: ​[fabljo]; plural fabliaux) is a comic, often anonymous tale written by jongleurs in northeast France between c. 1150 and 1400. They are generally characterized by sexual and scatological obscenity, and by a set of contrary attitudes—contrary to the church and to the nobility. Several of them were reworked by Giovanni Boccaccio for the Decameron and by Geoffrey Chaucer for his Canterbury Tales. Some 150 French fabliaux are extant, the number depending on how narrowly fabliau is defined. According to R. Howard Bloch, fabliaux are the first expression of literary realism in Europe.

Some nineteenth-century scholars, most notably Gaston Paris, argue that fabliaux originally came from the Orient and were brought to the West by returning crusaders.