In 1974 Riordan became part of the Illinois Drama Studio and acted in several productions including A Hatful of Rain, All My Sons and Zoo Story. Later he continued acting at Santa Monica Jr. College appearing with his wife Deborah in Moliére’s The Jealous Husband.

     In Los Angeles, Riordan collaborated with Pulitzer Prize winner Jason Miller on a mini-series (The Irish) and a movie of the week for CBS (Bless Me Father). He was a consultant on Oliver Stone’s The Doors, which led to his writing Stone’s biography. From1997-2000, Riordan created and co-starred in a local TV program, Kankakee Valley Prime Time with co-host Jaymie Simmon which featured stories about the community and comedy skits. The program was watched by a whopping 45% of households and won six Crystal Communicators and three Telly Awards and Riordan received a Chicago/Midwest Emmy Nomi¬nation for Writing. In the summer of 1999, James Riordan wrote, directed, and starred in Maddance which won Crystal Communicators for Drama, Writing, Acting and Directing. He has written several screenplays since including John Horse with Walt Alexander (Winner of Best Screenplay at the American Film Festival, the San Antonio Film Festival, the Dallas New Wave Cinema Awards and a finalist at the Las Vegas Black Film Festival and the Lucky Strike Film Festival). Most recently he completed Performance : The Ingrid Bergman Story