He is best known for portraying Cameron Frye in John Hughes' film Ferris Bueller's Day Off (1986), as well as television roles as Stuart Bondek on the ABC sitcom Spin City (1996–2002) and Connor Roy on the HBO series Succession (2018–2023), the latter earning him Primetime Emmy and Golden Globe Award nominations.

His other film credits include Bad Boys (1983), Three Fugitives (1989), Young Guns II (1990), Speed (1994), Star Trek Generations (1994), and Twister (1996).

[4] Alan played an annoying tourist named Doug Stephens on an ill-fated bus in the 1994 blockbuster Speed.

He later starred in the season two Scrubs episode "My Lucky Day" as a patient, and played reporter Steve Jacobson on the ESPN miniseries The Bronx Is Burning.

In 1998, Ruck guest-starred in the fifth episode of the HBO miniseries From the Earth to the Moon as the NASA engineer Tom Dolan.

In 2009, he had a minor role in an episode of Cougar Town: Frank, who has problems with his marriage due to a crush he had long ago on Jules, played by Courteney Cox.

In 2012, Ruck was cast in the ABC Family series Bunheads as the husband to Sutton Foster's character, Michelle.

In autumn 2016, Ruck began a 10-episode run on The Exorcist as Henry Rance, the husband (who has suffered mild brain damage in a vaguely explained accident) of Angela Rance (Geena Davis), better known as the adult Regan MacNeil, the tortured girl (played by Linda Blair) who is possessed by a demon in the 1973 hit film The Exorcist.

From 2018 to 2023, Ruck played the role of Connor Roy, the eldest son of a media magnate, in the HBO series Succession.

He was part of the cast's win for the Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Drama Series in 2022.

[9][10][11] Since 2008, he has been married to actress Mireille Enos, whom he met in 2005 while co-starring in the Broadway revival of Absurd Person Singular.