The Fat EP is an EP by the American punk rock band the Descendents, released in 1981 through New Alliance Records. It was the band's first recording with singer Milo Aukerman and established their presence in the southern California hardcore punk movement, with short, aggressive songs that represented a shift in style from their previous new wave and surf sound. The EP was re-released in later years as part of several compilation albums.

Descendents is an American punk rock band formed in 1977 in Manhattan Beach, California, by guitarist Frank Navetta, bassist Tony Lombardo and drummer Bill Stevenson as a power-pop/surf punk band. In 1979, they enlisted Stevenson's school friend Milo Aukerman as a singer, and reappeared as a melodic hardcore punk band, becoming a major player in the hardcore scene developing in Los Angeles at the time. They have released eight studio albums, three live albums, three compilation albums, and four EPs. Since 1986, the band's lineup has consisted of singer Milo Aukerman, guitarist Stephen Egerton, bassist Karl Alvarez, and drummer Bill Stevenson.