Sheridan started his film career in the late 1980s with small roles. His first on screen appearance was in the Whoopi Goldberg vehicle Jumpin Jack Flash. By the 1990s, he was playing the token family man, a role he would continue in both film and television, such as 1991's All I Want for Christmas. He also has played villains. In 1994 he played the character of Randall Flagg in the miniseries adaptation of Stephen King's The Stand. Other roles include Marty Stouffer in Wild America and the psychotic neighbor in Video Voyeur: The Susan Wilson Story. After a long history of performing Shakespeare on the stage, Sheridan appeared in Campbell Scott's production of Hamlet in 2000 as well as the Hamlet-inspired modern noir film Let the Devil Wear Black (1999). He co-starred in the improvisational film The Simian Line in 2001. He has also given supporting performances in The Ice Storm, Cradle Will Rock, Life as a House, and numerous TV movies.
Sheridan's acting career has encompassed theater, television, and feature film productions. Born in Pasadena, California, to a family of actors, he earned a Tony nomination in 1987 for his performance in the revival of Arthur Miller's All My Sons. After several TV movie appearances, Sheridan landed a starring role as Lawyer Jack Shannon on Shannon's Deal, which ran for one season in 1990. His later television roles include Dr. John Sutton on Chicago Hope (from 1995 to 1996).
More recently, Sheridan played Capt. James Deakins in the television series Law & Order: Criminal Intent. Late in the 2004–2005 season, Sheridan began wearing an eyepatch as he began showing the symptoms of Bell's palsy. This was written into the show; however, Deakins was written out of the series at the end of the 2005–2006 season, at Sheridan's request. His character was replaced by Capt. Danny Ross, played by Eric Bogosian.
Sheridan played alongside Jane Seymour in the Hallmark Channel movie Dear Prudence as Detective Eddie Duncan. On November 6, 2008, Sheridan guest starred as an evening news anchor on the ABC dramedy Eli Stone.
From 2009 to 2010, Sheridan starred in NBC's Trauma as Dr. Joseph "Joe" Saviano. In 2010 Sheridan starred in the movie Handsome Harry, a drama. He played speechwriter Mark Salter in the political film Game Change.
In the fall of 2012, Sheridan signed on to play a recurring role on CW's Arrow, playing Oliver Queen's father who sacrificed himself so that his son could live on a deserted island due to their ship being destroyed in the middle of the ocean. He occasionally reappears, once as a ghost to his son while he's still on the island and also through a flashback centered around his character; the rest of his appearances so far have been through pictures.
Sheridan played Jim Sullivan in the 2015 film Spotlight.
