A native of Ireland, Damien O'Donnell graduated from Coláiste Dhúlaigh College in 1987 with a degree in Communication and Media Production. He co-founded Clingfilms, a small Dublin film company, with three friends, then went on to write and direct 35-Aside (1995), a humorous short film that won awards from films festivals around the world.
After screenwriter Ayub Khan Din's girlfriend saw 35-Aside on BBC2, Khan Din offered him the job of directing East Is East (2000), based on his hit play. Produced by BBC Films and Film Four, the movie won a 2000 BAFTA award for Best British Film and a Best Debut award for O'Donnell at the 2000 Empire Awards.
He began working on another project for Film Four that would have starred Anthony Hopkins and Javier Bardem, but the financing fell through, so instead O'Donnell took on the heartwarming film Heartlands (2002). Unfortunately, it was only released in the UK and relatively few people saw it.
His next film, Inside I'm Dancing, won the Audience Award at the Edinburgh International Film Festival. The story about two men with disabilities was released North America as Rory O'Shea Was Here (2005).