Life and career
Education and early career
Allan attended the University of Washington, where he majored in Drama. While in college, he supported himself working as a radio and television announcer and sportscaster. In the 1960s, he appeared in several Broadway productions such as Viva Madison Avenue!, Oliver!, and .
Daytime television roles
Allan starred in several soap operas. He made his debut as trouble-making Ace Hubbard on Love of Life in 1964. He played college professor Paul Britton on The Secret Storm in 1964–65. Allan was one of many actors to play Paul, who was involved with the show's leading heroine, Amy Ames. Allan replaced his future Santa Barbara co-star Nicolas Coster in the part. He is best known for his role as Don Craig in Days of Our Lives, which he played from 1971 to 1985, his exit taking place as many of the show's veteran cast members were being written out so the show could focus on younger characters. His departure from Days of Our Lives was unpopular among his fans. His character was abruptly written out with minor explanation. He gained a new audience when he took over the role of C. C. Capwell in Santa Barbara from 1986 to 1993. After his time on Santa Barbara, Allan had a recurring role in Beverly Hills, 90210 playing Rush Sanders.
In 2004, he started playing the role of Edward Quartermaine in General Hospital.
Allan's most notable television role outside of soap operas was when he starred on Lassie from 1968 to 1970 as Forest Ranger Scott Turner, who along with fellow ranger Bob Erickson (played by Jack De Mave) served as the collie dog's main human companion during that period.
He appeared in numerous made-for-television movies. He hosted Celebrity Bowling during the 1970s as well as a game show pilot, Temptation, in 1981 for Ralph Andrews and Columbia Pictures Television.
In 1973 Allan was a featured character in an episode of Adam-12 titled "Capture".
Allan wrote a book, Please, Spell the Name Right, in reference to his name often being spelled incorrectly. The book is about his experiences of 50 years as an actor working with other actors and was released in November 2004.