William James Remar (born December 31, 1953) is an American actor. Highlights of his four decades-long career in film include his portrayals of Ajax in The Warriors (1979), Albert Ganz in 48 Hrs. (1982), Dutch Schultz in The Cotton Club (1984), and Jack Duff in Miracle on 34th Street (1994). In television, he is best known for playing Richard Wright in Sex and the City (2001–2004), and Harry Morgan, the father of the title character, in Dexter (2006–2013) and Dexter: Resurrection (2025). Since 2009, he has done voice-over work in ads for Lexus luxury cars. Remar studied acting at the Neighborhood Playhouse School of the Theatre in New York City.

Remar's more recent roles include Frank Gordon in Gotham from 2016 to 2019; Peter Gambi in Black Lightning from 2018 to 2021; Secretary of War Henry L. Stimson in Oppenheimer in 2023 and General Francis Shaw in It: Welcome to Derry (2025).

William James Remar was born in Boston, Massachusetts, on December 31, 1953. He is the son of Elizabeth (née Boyle), who worked in mental health affairs for the state of Massachusetts, and Roy Remar, who was an attorney. His father was of Russian-Jewish descent, while his mother was a native of England and of Irish descent. He has three sisters and two brothers. Remar grew up with his family in Newton, Massachusetts.

Remar dropped out of high school when he was 15, although he attended what he described as "kind of an alternative school" for a year afterwards. He then traveled around the United States, briefly playing guitar in a rock band. Eventually, he returned home and went back to high school, although he decided not to attend college after graduating. Remar has said he decided to become an actor when he was 20; after he was laid off from his job as a roofer, he remembered a previous job performing at a summer camp, and said he would give himself three years to attempt an acting career before he would try something else.

In Florida, Remar earned a role in a state production of Cross and Sword. Afterwards, he studied at the Neighborhood Playhouse School of the Theatre, but was not asked back after his first year, which he described as "a devastating experience". Remar continued searching for other acting jobs, eventually landing the part of Kenickie in a touring production of Grease, and also performed at the Ensemble Studio Theatre, before making his film debut in On the Yard.

Remar has spent the majority of his film career playing villains. He portrayed the violent gang member Ajax in the cult film The Warriors (1979), and the murdering sociopath Albert Ganz in the hit 48 Hrs. (1982). Both films were directed by Walter Hill. Remar also played real-life 1930s-era gangster Dutch Schultz in The Cotton Club (1984).

In contrast to these roles, Remar starred in the film Windwalker (1980) as the young Cheyenne Windwalker, for which he spoke his lines in the Cheyenne language. He also portrayed a gay man in the film Cruising (1980). That same year, Remar had a cameo in the Western The Long Riders (1980) in a bar fight scene with David Carradine.

He was the star of the film Quiet Cool (1986) and was cast as Corporal Hicks in the science-fiction/horror film Aliens (1986), but was replaced by Michael Biehn shortly into filming after being arrested for drug possession. At least one piece of footage featuring Remar made it into the final version of the film: when the Marines enter the processing station and the camera tilts down from the Alien nest, though Remar is not seen in close-up. He is also filmed from the back as the Marines first enter the compound on LV-426 and when "Hicks" approaches the cocooned woman, again filmed from the rear so the viewer is unable to tell it is Remar and not Michael Biehn.