Insomniac or The Insomniac may refer to:
- A person who has insomnia
- Insomniac (Green Day album)
- Insomniac (Enrique Iglesias album)
- "Insomniac" (song), a song by Echobelly
- "Insomniac", a song by Billy Pilgrim
- Insomniac with Dave Attell, a television series
- Insomniac Games, an American video game developer
- Insomniac Press, a Canadian independent book publisher
- The Insomniac, a 2009 Singaporean film noir