He appeared in approximately 129 films and television programs between 1920 and 1974. During the 1920s and 1930s, he became a popular child and juvenile actor appearing in early Our Gang comedies, but he is best known for the role of Billy Batson in Adventures of Captain Marvel.

Coghlan later served 23 years as an aviator and officer in the US Navy from 1942 to 1965. After retiring from the Navy, he returned to acting and appeared in television, films, and commercials.