- At age 8, relocated with his family from Scotland to Illinois.
- Performed at an Opryland theme park in Tennessee before moving to London and landing the role of Billy Crocker in the 1989 West End stage revival of Cole Porter's Anything Goes.
- Dabbled in American television as a spoiled rich hunk in Darren Starr's short-lived prime-time soap Central Park West (1995).
- Has released several solo albums, including Reflections From Broadway (2000), John Barrowman Swings Cole Porter (2004) and Aspects of Lloyd Webber (first released in 1997 and re-released in 2007), Music, Music, Music (2008) and The Very Best of John Barrowman (2011).
- In 2005, he appeared on the BBC's refurbished Doctor Who as con artist Captain Jack in a five-episode stint that led to his own 2007 spin-off, Torchwood.
- Coauthored several books with his sister, Carole, including the memoirs Anything Goes (2008) and I Am What I Am (2009), and the novel Hollow Earth (2012).
- Cofounded Dreamers Workshop, a motivational program that teaches kids about theater.