Tim Armstrong (full name Timothy Lockwood Armstrong, born November 25, 1966) is a musician. He was born in Oakland, California to a hardworking mother and an alcoholic father. He has two older brothers and was the youngest of the family. He showed interest in music at an early age.

He was in the punk/ska band Operation Ivy until its demise, he then founded two relatively unsuccessful bands called the Dance Hall Crashers and The Downfall but later went on to greater fame with the very successful Rancid.

He founded Hellcat Records and plays in The Transplants with Rob Aston and Travis Barker (of Aquabats and Blink-182 fame). He also writes songs for other artists, including Pink and Gwen Stefani.

Tim has never had a drivers' licence (due to dyslexia), nor a bank account. He also overdosed twice in his younger years and recovered fully both times.

He married Brody Dalle of The Distillers in 1997. They divorced in early 2003.