William Atherton's career has spanned motion pictures, Broadway and television. He first achieved international recognition as the lead in Steven Spielberg's debut feature The Sugarland Express and next starred in John Schlesinger's The Day of the Locust, Robert Wise's The Hindenburg and Richard Brooks' Looking For Mr. Goodbar. He is known worldwide for what have become his signature film characters: the TV reporter, Dick Thornburg in Die Hard I and 2; the EPA official, Walter Peck in Ghostbusters; Professor Hathaway in Real Genius and the mad scientist, Dr. Faulkner in Bio-Dome. Among his more than 30 feature films are co-starring roles in John Landis's Oscar, Bill Duke's Hoodlum, Richard Pearce's No Mercy, Alan J. Pakula's The Pelican Brief, Costa Gravas' Mad City and Ed Zwick's The Last Samurai.

On television, he has starred in several mini-series including the classic western Centennial. His many made-for-TV movies include TNT's production of Joan Didion's Broken Trust and his portrayal of Darryl F. Zanuck in HBO's Golden Globe winner Introducing Dorothy Dandridge. Atherton was recently a recurring series lead on NBC-TV's Life and portrayed Principal Reynolds in the last season of Lost.

Atherton has originated roles on and off Broadway for many of America's leading playwrights. These include the title character in Joe Papp's production of David Rabe's The Basic Training of Pavlo Hummel, the role of Ronnie in John Guare's The House of Blue Leaves and Bing Ring Ling in his Rich and Famous. He starred in the Broadway premiere of Arthur Miller's The American Clock and the Tony-winning revival of Herman Wouk's The Caine Mutiny Court Martial. Among his more than twenty well-known productions are the New York premieres of Franz Kafka's The Castle and Kressman Taylor's Address Unknown. For his work on the stage he has received the Drama Desk Award, the Outer Circle Critics Award, the Theatre World Award and nominations for an Obie and Chicago's Joseph Jefferson Award.

Current work includes Clinical, a new thriller on Netflix and the upcoming independent film, Lowlifes. Atherton was also seen in the SyFy Channel's hit TV series, Defiance, as the recurring character, Viceroy Mercado.