Osker was a punk trio active in the late 1990s and early 2000s in the United States, in Los Angeles, led by singer/guitarist Devon Williams.
About their debut album Treatment 5, Allmusic gave a positive review of 3/5, writing "Treatment 5, Osker's debut album, is a rather typical release for the Epitaph label -- aggressive punk with unhinged, snotty vocals and lyrics that alternate between goofy humor and angst-filled catharsis."
In 2001, the group released their second (and final) studio album, Idle Will Kill. During this year, the group also appeared in the movie Crazy/Beautiful, performing the songs "Fuck Me" and "Alright" from Treatment 5.