Tom Hanks, Robin Williams, and Others

Despite the immense popularity surrounding its main cast—Ron Howard’s sincere Richie, Henry Winkler’s effortlessly suave Fonzie, and the beloved parental figures Tom Bosley and Marion Ross—Happy Days also captivated audiences with its remarkable parade of guest stars who graced Arnold’s and the Cunningham household. Some were established names, others were fresh faces, and a few even blossomed into superstar status.

Among those names, Robin Williams is memorable for debuting his Mork from Ork persona on Happy Days, which subsequently led to ABC approving Mork & Mindy. Tom Hanks, years shy of his first Oscar, faced off with Fonzie in a hilarious feud over a past grievance. Back then? Their futures were uncertain, but their legacies became undeniable.

Then came the veterans—like Danny Thomas and Lorne Greene—who infused their guest appearances with gravitas and a nostalgic Hollywood allure. Familiar TV personalities like Maureen McCormick and Christopher Knight stepped out of The Brady Bunch world for a fresh venture, while Laverne & Shirley found its unofficial beginnings through Penny Marshall and Cindy Williams’ guest roles.

So, let’s give the jukebox a Fonzie smack and explore 10 unforgettable guest stars who made their mark on Happy Days.

1. Robin Williams

Episode: “My Favorite Orkan” (Season 5, Episode 22)

Role: Williams brought Mork, an extraterrestrial from Ork, to Milwaukee to study human quirks. After Richie claims to have seen a UFO, Mork appears in his room, intending to take him back to Ork as a human specimen. The episode humorously captures Mork’s struggles to grasp earthly customs—like shaking hands—and features a psychic duel between Mork and Fonzie, who employs his famous “thumb power” against the alien. Initially, the episode concluded with Richie waking up to realize it was all a dream. Yet, for syndication, an alternate ending was shot where Mork reports to his superior, Orson, stating he had erased everyone’s memory, making the events genuine in the series’ context. ​

Fun Fact: This episode served as a backdoor pilot for Mork & Mindy, which premiered in 1978, catapulting Robin Williams to stardom. His audition was famously quirky; when asked to sit down, he performed a headstand, leading producer Garry Marshall to joke he was “the only alien who auditioned.” His improvisational flair and unique comedic vibe during filming captivated the cast and crew, paving the way for the spin-off.

2. Tom Hanks

Episode Title: “A Little Case of Revenge” (Season 10, Episode 5)​

Role: Tom Hanks shines as Dr. Dwayne Twitchell, a karate enthusiast returning to Milwaukee for vengeance against Fonzie over childhood payback. After challenging Fonzie to a duel, Hanks becomes the first character to land a direct blow on Fonzie, sending him crashing through a stained-glass window at Al’s Drive-In.

Fun Fact: This episode aired on November 9, 1982, shortly after Bosom Buddies wrapped its two-season run. While Hanks was already gaining recognition, it was his comedic turn on Happy Days that caught the eye of Ron Howard, helping him land the lead role in Splash (1984)—his ticket to the big screen. Interestingly, years later, both Hanks and Winkler collaborated on the 1996 film That Thing You Do!, directed by Hanks, though Winkler humorously noted he wasn’t offered a part.

3. Danny Thomas

Episode Title: “Grandpa’s Visit” (Season 5, Episode 14)

Role: Danny Thomas appears as Sean Cunningham, Howard’s father. In this episode, Grandpa Cunningham visits, bringing old-school values and a vibrant personality. His traditional beliefs cause lighthearted generational conflicts, especially with Richie and Joanie, while Marion and Howard try to mediate. The narrative explores Howard’s family history, offering viewers a glimpse into his upbringing.

Fun Fact: This episode, which aired on January 3, 1978, marked a significant guest appearance for Danny Thomas, famous for Make Room for Daddy (also known as The Danny Thomas Show). His take on Howard’s father added depth to the episode and provided a touching exploration of familial generational differences.

4. Lorne Greene

Episode Title: “Hollywood, Part 1” (Season 5, Episode 1)

Role: Lorne Greene had a brief, uncredited cameo as his beloved character Ben Cartwright from Bonanza, providing a sprinkle of classic TV nostalgia. In this plot, Fonzie and Richie travel to Hollywood for a movie screen test.

Fun Fact: Greene’s cameo was part of a larger tribute within the two-part Hollywood storyline, featuring real-life celebrity appearances to highlight Fonzie’s rising fame. While best recognized as Ben Cartwright in Bonanza, Greene was a familiar face on ABC, and his cameo celebrated both classic television and the network’s star-studded roster.

5. Penny Marshall & Cindy Williams

 

Episode Title: “A Date with Fonzie” (Season 3, Episode 22)

Role: Penny Marshall and Cindy Williams debut as Laverne DeFazio and Shirley Feeney in “A Date with Fonzie.” Fonzie sets up a double date for himself and Richie with Laverne and Shirley, two spirited workers from the Shotz Brewery. The episode humorously examines the dynamics of the double date, revealing the characters’ contrasting attributes and leading to comical twists.

Fun Fact: Even though Cindy Williams previously acted on Happy Days as a different character in season 1, episode 3, this episode genuinely launched Laverne and Shirley within the Happy Days universe. Their guest appearances were so effective that it directly led to the inception of Laverne & Shirley, which debuted the following year and turned into a massive hit.

6. Maureen McCormick

Episode Title: “Cruisin'” (Season 2, Episode 16)

Role: Maureen McCormick portrays Hildie, one of three girls that Richie, Potsie, and Ralph encounter while cruising in Howard’s DeSoto after Marion inadvertently damages Richie’s vehicle. The boys’ attempts to win the girls over lead them into hot water when they learn the girls are dating members of a local gang called the Dragons. A drag race orchestrated by Fonzie follows, culminating in the revelation that the girls were using the boys to provoke their boyfriends.

Fun Fact: This episode signified Maureen McCormick’s first significant guest role post-The Brady Bunch in 1974.

7. Christopher Knight

Episode Title: “Be My Valentine” (Season 5, Episode 20)

Role: Christopher Knight appears as Binky Hodges. In “Be My Valentine,” Joanie Cunningham is eager for her date, Binky, who is delayed. While she waits, Joanie envisions romantic scenarios involving her loved ones, leading to several musical dream sequences. Eventually, Binky arrives with a locket for Joanie, deciding they will spend their evening at Inspiration Point.

Fun Fact: This episode was broadcast on February 14, 1978—Valentine’s Day itself. Knight, known for playing Peter Brady on The Brady Bunch, appeared when many 1970s television stars were making crossovers onto popular sitcoms. His involvement offered added promotional value due to The Brady Bunch’s enduring popularity in reruns.

8. Charlene Tilton

 

Episode: “They Shoot Fonzies, Don’t They?” (Season 4, Episode 8)

Role: Charlene Tilton stars as Jill Higgins. In this episode, Joanie is cut from the cheerleading squad by confident and competitive Jill. In an effort to prove herself, Joanie enters a dance marathon at Arnold’s Drive-In, enlisting Fonzie as her partner. Even though Fonzie is fatigued from pushing his broken motorcycle for twelve miles, he joins Joanie to support her. The contest culminates in an exciting showdown between Joanie and Fonzie versus Jill and her partner Bubba, with Joanie’s team ultimately winning.

Fun Fact: Airing on November 1, 1976, this episode marked one of Tilton’s initial television appearances. Just two years later, she landed the iconic role of Lucy Ewing on Dallas. The episode’s title is a nod to the 1969 film They Shoot Horses, Don’t They?, which centers around a grueling dance marathon.

9. Nancy Walker

Episode Title: “The Third Anniversary Show” (Season 4, Episode 17)

Role: Nancy Walker guest stars as Nancy Blansky, Howard Cunningham’s cousin from Las Vegas. In this celebratory clip show, Richie and Joanie plan a surprise party for their parents’ wedding anniversary. Nancy’s arrival introduces a lively dynamic to the gathering, displaying her as a vibrant, showbiz-savvy relative. Her character connects the nostalgic flashbacks with the current celebrations, infusing both humor and fresh perspectives.

Fun Fact: This episode aired on February 4, 1977, and acted as a backdoor pilot for Blansky’s Beauties, a spin-off that premiered just eight days later, on February 12, 1977 ​. In the new series, Nancy Blansky is depicted as a seasoned Las Vegas entertainment pro who becomes a den mother to a group of aspiring showgirls. Although introduced in the 1950s setting of Happy Days, Blansky’s Beauties is situated in the contemporary 1977 environment, forging a unique cross-era bond between the two series.​

10. Jack Dodson

Episode Title: “A Sight for Sore Eyes” (Season 3, Episode 23)

Role: Fonzie faces relentless headaches and hesitantly visits Dr. Malph, who diagnoses him with a vision issue requiring glasses. Fonzie worries that wearing glasses may hinder his cool persona, leading to humorous endeavors from his friends to persuade him otherwise.

Fun Fact: Jack Dodson is renowned for his role as Howard Sprague on The Andy Griffith Show. His recurring part as Dr. Mickey Malph on Happy Days allowed him to share his gentle charm with a new audience. He appeared in various episodes across seasons, establishing Dr. Malph as one of the few adult characters outside the Cunningham family to interact regularly with the younger cast.

Enjoy much more about the world of ‘Happy Days’

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