Richie and Joanie had an older brother named Chuck, who was played by two different actors, and who only appeared during the first season of the show, because the character of Chuck was written off the show. This plot plot has since absorbed into popular culture: known as "Chuck Cunningham Syndrome," it refers to a character's (either leading or supporting) unexplained disappearance from a series.

In Season 5, in the 3 part special (episodes 89-91) the whole gang heads to Hollywood. It is here that Fonzie jumps over a caged shark on water skiis. Today a TV show is said to have "jumped the shark" when it has passed its peak and fans feel a significant drop in quality. The phrase was popularized by the website www.jumptheshark.com.

There is an excellent pop video that honours Happy Days. It is by the band Weezer. The song is "Just Like Buddy Holly," and features the band performing it in the cafe. Most of the cast also turn up in it by the wonders of camera trickery.