He was known for playing Chuck Cunningham in the first episodes of Happy Days, as well as his appearances in films such as Never Say Never Again, Death Wish 3, Willow, and Superman III.

[4] In 1994, he starred as John Garrideb in "The Mazarin Stone" from Granada TV's Sherlock Holmes series.

After that, Chuck was written off the show completely with later episodes depicting the Cunningham family with only two children with Richie as the elder.

He played a warrior in the George Lucas production Willow, directed by his Happy Days brother, Ron Howard.

In 2009, O'Herlihy returned to the big screen as Sheriff Vaines in the follow-up to Neil Marshall's cult horror film, The Descent Part 2, and over a decade later returned to the screen again to play the leading role of writer John Anderson for director Nic Saunders in Queen of the Redwood Mountains, a film inspired by the authors of the Beat Generation, and due for release in 2021.