Ironside specializes in playing villains and tough-guys. One of his first roles was as evil telepath Darryl Revok in Scanners (1981), an early film by David Cronenberg. He played the role of a serial killer, Colt Hawker, in the 1982 slasher film Visiting Hours, directed by Jean-Claude Lord, and appeared as Miler Crane in The A-Team episode "Taxicab Wars" (1983). His breakthrough role was as cynical anti-hero Ham Tyler in the television miniseries V: The Final Battle (1984). He is also known for his roles in Top Gun (1986) as Naval Aviator Lieutenant Commander Rick "Jester" Heatherly, Extreme Prejudice (1987) as Major Paul Hackett, Watchers (1988) as a conscience-free mutant Assassin, and Total Recall (1990) as Richter, the murderous henchman of Ronny Cox's villain Cohaagen. Ironside played the villainous General Katana in the science fiction sequel Highlander II: The Quickening (1991) and, after a brief stint in ER's inaugural season, he was tapped to replace Roy Scheider as captain of the high-tech submarine seaQuest in the third season of seaQuest DSV as Captain Oliver Hudson. However, NBC cancelled the series after only thirteen episodes with Ironside as the star. In 1992, he starred as M. Emmet Walsh's brother in David Winning's thriller Killer Image. In 1997, Ironside was reunited with Total Recall Director Paul Verhoeven for Starship Troopers. He appeared in The Perfect Storm (2000) and The Machinist (2004). He starred in the film Chaindance as a small-time crook, unable to make it on the outside, who was paired up with a handicapped man. Ironside starred as Resistance General Hugh Ashdown in Terminator Salvation, reunited with his co-star from The Machinist, Christian Bale.