Robert Reed Carradine (/ˈkærədiːn/ KARR-ə-deen; born March 24, 1954) is an American actor. A member of the Carradine family, he made his first appearances on television Western series such as Bonanza and his brother David's TV series, Kung Fu. Carradine's first film role was in the 1972 film The Cowboys, which starred John Wayne and Roscoe Lee Browne. Carradine also portrayed fraternity president Lewis Skolnick in the Revenge of the Nerds series of comedy films.

Carradine is the son of actress and artist Sonia Sorel (née Henius) and actor John Carradine. He is one of many actors in the Carradine family. He is the brother of Christopher and Keith Carradine, paternal half-brother of Bruce and the late David Carradine, and maternal half-brother of Michael Bowen. His maternal great-grandfather was biochemist Max Henius, and his maternal great-grandmother was the sister of historian Johan Ludvig Heiberg.

Carradine's parents divorced when he was 2 years old. A bitter custody battle led to his father gaining custody of him and his brothers, Christopher and Keith. During the custody battle, the children spent three months in a home for abused children as wards of the court. His brother Keith said of the experience, "It was like being in jail. There were bars on the windows, and we were only allowed to see our parents through glass doors. It was very sad. We would stand there on either side of the glass door crying".

Carradine was raised primarily by his stepmother, his father's third wife, Doris Grimshaw, and believed her to be his mother until he was introduced to Sonia Sorel at a Christmas party when he was 14 years old. While still in high school, Robert lived with his half-brother, David, in Laurel Canyon, California. Under David's care he indulged in two of his major interests: race car driving and music. He and David belonged to a musical quartet that performed in small clubs in Los Angeles and San Francisco.

Carradine made his film debut in 1972 in The Cowboys with John Wayne. He was also featured in a short-lived television series, of the same name, based on the movie. He made an appearance as a killer in the Martin Scorsese film Mean Streets shooting to death the character played by his brother, David.

During this time he worked with David on some independent projects including a biker film called You and Me (1975) and an unreleased musical called A Country Mile. He also did camera work for David's cult classic Vietnam War-inspired Americana which was not released until 1983.

In 1976, Carradine had the opportunity to demonstrate on screen what he considered to be his "first ambition", car racing, when he played Jim Cantrell in Paul Bartel's Cannonball. In the film Robert's character wins the cross country road race, beating the favorite, Coy "Cannonball" Buckman, played by his brother, David. In 1977, Robert became a snack for the vengeful killer whale in the Jaws imitation film Orca.

Robert also played with other Hollywood offspring in the 1977 film Joyride, where he starred with Desi Arnaz, Jr., Melanie Griffith and Anne Lockhart (daughter of June Lockhart) in a film about young Californians driving up to Washington and Alaska to seek their fortunes.