He graduated from Crespi Carmelite High School and attended Pierce College for two years. He attended American Theater Arts, a combined conservatory and theater company in Los Angeles, where he appeared in the plays Richard's Cork Leg by Brendan Behan and Private Life of the Master Race by Bertold Brecht. In 1983, he and his wife, Vivian, moved to New York City, where he took odd jobs like installing drapery to support his family. He joined the off-off-Broadway Cucaracha Theater on Greenwich Street.

Donovan married Actress Vivian Lanko in 1984; they have two sons. They lived in New York City for many years before relocating to Vancouver, Canada.

In 2009, he starred opposite Virginia Madsen in The Haunting in Connecticut. Recently he was seen in The Sentinel with Kiefer Sutherland and Michael Douglas as well as The Quiet with Edie Falco. In 2007 he appeared in the suspense horror film Wind Chill. Other recent film appearances include The United States of Leland, The Opposite of Sex, Living Out Loud, In a Savage Land, Hollow Reed, Onegin, and Nadja.

In 2010, Donovan wrote, directed and starred in Collaborator, portraying a once-successful Playwright who is taken hostage while visiting his mother and childhood home.

Donovan made his television series début in Peter Berg's Wonderland. His recent TV credits include Masters of Horror (episode "Right to Die"); the FX telefilm RFK and the Fox series Pasadena. Other television credits are The Great Gatsby, and HBO's When Trumpets Fade. In 2011 he took a major role in the Starz original drama series Boss. In 2014 he starred in the Lifetime post-apocalyptic series The Lottery.