After writing for the CBS series "Nash Bridges" and the series "Angel," Ryan created and executive produced the first original drama series for FX, "The Shield," in 2002. Ryan's work on the pilot episode of that series yielded an Emmy Award nomination for Outstanding Writing for a Drama Series. In 2003, the series was awarded the Golden Globe for Best Drama Series and has earned several other Emmy nominations.

Ryan earned a joint degree in Economics and Theatre from Middlebury College, where he first began writing plays. He lives in Los Angeles with wife, actress Cathy Cahlin Ryan, and their two children.