Michael Cassidy kick-started his acting career after graduating from the prestigious two-year conservatory program at The New Actors Workshop in New York in 2003. He is best known for is role as Zach Stevens, which he portrayed throughout the entire second season of The O.C
In 2007, Cassidy joined the cast of The CW's Hidden Palms in the lead role as Cliff Wiatt. He also starred in the long-running hit Smallville as Grant Gabriel, a love interest of Lois Lane who actually turned out to be the cloned and aged brother of Lex Luthor. Other credits include the Showime hit series Masters of Sex; Josh Schwartz's web-series Rockville CA; The CW's Privileged; ABC's Castle, Scandal and Happy Endings; and NBC's Are You There, Chelsea? and the pilot Pink House.
Cassidy has also been featured in several feature films, including Zoom, opposite Tim Allen, Courtney Cox Arquette and Chevy Chase. Last year, he appeared in the Oscar winning film Argo, directed by Ben Affleck.