Kilroy was here is an American expression that became popular during World War II, typically seen in graffiti.

Kilroy Was Here may also refer to:

• Kilroy Was Here (1947 film), an American comedy film
• Kilroy was Here, a song from the 1968 album Move by The Move
• Kilroy Was Here (album), a 1983 album by Styx
• Kilroy Was Here (1983 film), a short film made to tie in with the Styx album
• Killroy Was Here (2022 film), an American horror anthology film based on the graffiti phenomenon