"F.S.O." (abbreviation of Fuck Shit Off) is a song by Australian rock band Regurgitator. The song was released in February 1996 as the band's first commercially released single and first single from the band's debut studio album Tu-Plang. The single peaked at number 51 in Australia.

Ben Ely said, "Quan wrote this about his sister-in-law and how she got married to this guy who turned out to be a brute and was violent with her. This song is his anger at the situation. I love how it sounds like an angry song, though it's a song about not tolerating someone else's anger."

Quan Yeomans said, "I was never particularly thrilled with my vocals on this one, but it has a punk urgency and ugliness about it that is apt for the idea behind it."^[1]