Born in downtown Toronto, John Cassini has gone on to build a successful film, stage and television career in both Canada and the U.S. Cassini was a founding member of the Third Street Theater in Los Angeles. While there, he directed several plays and starred in the original stage production of They Shoot Horses Don't They?

Cassini's television credits include NYPD Blue, ER, The Practice, Da Vinci's Inquest (for which he got a Gemini nomination) and a recurring role on Chris Haddock's CBS drama The Handler. His many film credits include Alive, Seven, The Game, Get Carter and Paycheck.

Cassini also co-wrote, produced, and directed the short film Freedom and went on to play the lead role in Break A Leg, a feature film which he produced and co-wrote with his brother Frank. When Cassini and his wife returned to Canada to raise their son, he took on the role of Yuri Kukoc on CTV's Robson Arms, for which he won a Leo Award for Best Actor.