Laneuville began acting while attending Audubon Junior High School in the Crenshaw, Los Angeles, District. He often played juvenile characters younger than his own age. He appeared in several musicals staged at Audubon by drama teacher Mario Lomeli, including Bye Bye Birdie, Annie Get Your Gun, and Oklahoma!. While taking drama courses at nearby Susan Miller Dorsey High School, he began acting professionally, co-starring as a troubled youth in an award-winning television movie and becoming a semi-regular cast member on Room 222, including one episode in which he appeared with his future Force of One co-star, Chuck Norris. He appeared in three episodes of Sanford and Son, as Esther's adopted son. In 1982, he landed the role of Luther Hawkins in the television series St. Elsewhere. He stayed with the series until it ended in 1988.
As his directing career took off, Laneuville's acting career continued only sporadically, usually in small cameo roles. His most recent on-camera appearance was in 2002, in a guest role as Dr. Lamar in the TV series Scrubs. He also appeared in the Fear of a Black Hat (1994), a mockumentaryparodying 1990s hip-hop culture.