Films:
* A Summer Place (1959): Donahue's breakout role, a romantic drama that became a huge box office success.
* Tall Story (1960): A romantic comedy starring Donahue as a basketball player.
* The Last Time I Saw Archie (1961): A crime drama about a missing boy.
* The Sundowners (1960): A Western starring Robert Mitchum and Deborah Kerr, in which Donahue played a supporting role.
* Parrish (1961): Another romantic drama with Donahue as a young man who falls in love with a wealthy woman.
* Frontier Gun (1961): A Western about a lawman in the Old West.
* Donovan's Reef (1963): A comedy set in the South Pacific starring John Wayne and Lee Marvin, in which Donahue played a minor role.
* The Lively Set (1964): A romantic comedy with Donahue as a musician.
* The Adventures of the Lone Ranger (1956): Donahue plays a young, reckless gambler.
* The Young Land (1960): A Western starring Patrick Wayne and Richard Boone, in which Donahue plays a rancher.
* The Enemy Below (1957): A World War II submarine film starring Robert Mitchum, in which Donahue had a minor role.
* **The Adventures of the
Outlaw Josey Wales (1976):** Clint Eastwood's Western features Donahue in his last film role.
Television:
* The Barbara Stanwyck Show (1960-1961): Donahue starred in this series alongside Barbara Stanwyck.
* Surfside Six (1960-1962): He starred as a private investigator.
* The Man from U.N.C.L.E. (1964-1968): Donahue appeared in several episodes of this popular spy series.
* The Love Boat (1977-1986): Donahue had a recurring role as a character named "Captain" in this popular television series.
* Fantasy Island (1978-1984): He also made several appearances in this popular series.
* Murder, She Wrote (1984-1996): Donahue had a guest role in this popular series.
Donahue's career slowed down in the late 1960s and 1970s, but he continued to work in television and occasionally in films until his death in 2009.
Please note that this is not an exhaustive list but includes some of his most notable projects. You can find more information on his career online and on IMDb.