Top 10 Best Young Sheldon Guest Stars

Even if this name doesn’t ring a bell, you might still recognize Steve Burns as Steve from the Nickelodeon kids show, “Blue's Clues.” On “Young Sheldon,” Burns plays Nathan, a middle-aged comic book nerd the title character becomes friends with, and someone Sheldon’s Meemaw certainly doesn’t appreciate her grandson being around at first. Nathan ends up being a good casual friend for Sheldon, though he may be too old to be hanging out with a kid. Playing Nathan isn’t the only contribution Burns has made to “Young Sheldon” as he’s also supplied the show’s theme song, “Mighty Little Man.”

This “The Kids in the Hall” member has appeared in a few episodes playing an obnoxious wealthy businessman named Gary O’Brien. The university Sheldon attends initially wants him to dine with O’Brien in the hopes that the businessman will cut the university a big check after meeting the prodigy. However, our protagonist, not feeling that Mr. O’Brien is his intellectual equal, tells him off in blunt Sheldon-esque fashion. Foley has since returned in the role, with the character becoming even more eccentric. It’s great to watch Sheldon being forced to put up with O’Brien’s absurdity.

When Sheldon develops a pimple, the comedic duo appear, Penn as a personified version of acne and Teller as his partner, pus. Together, they break down the significance and implications of Sheldon’s situation, as Penn discusses the details in a lively manner while Teller sits quietly and plays off him. According to TVLine, series co-creator Steven Molaro and the team thought Penn Jillette would be “perfect” when deciding who to bring on as the zit. Watching the star’s over the top delivery that manages to be both obnoxious and charismatic, we would have to say this casting decision was the right call.

The late actor manages to be both intimidating and hilarious as Sheldon’s engineering professor, an armed services veteran who runs his class with discipline. At first, Sheldon appreciates this strict teaching style. But that changes once it forces him to struggle with a difficult assignment. Sheldon rarely meets his match, so it’s nice to see Reddick’s character put him in his place without breaking a sweat. It’s a long running gag in “The Big Bang Theory” that Sheldon has disdain for engineers, and Reddick’s fantastic appearance helps explain the reason why that is.

In the third season, this country music superstar made her debut on the show as June, a hairdresser and friend of Sheldon’s Meemaw, Connie. With a successful acting career which included her own popular sitcom, McEntire and her folksy, southern energy are a natural fit for “Young Sheldon” and its Texas setting. With her charming, bubbly personality on the show and in real life, Reba is always a delight to see whenever she stops by. Unfortunately, she doesn’t bring her singing talent with her, as her character can’t carry a tune in a bucket.

The comedy veteran plays Gene Lundy, an oddball drama teacher at Sheldon’s high school. Passionate about his craft, Mr. Lundy is up to play any role available, whether it’s the dark lord Satan or little orphan Annie. And he’s not afraid to ham up his performance for the crowds, either. In later episodes, the character participates in business hustles such as creating an exercise tape and pushing a cosmetics pyramid scheme. Leave it to the man who played George Costanza on “Seinfeld” to give life to a character so shameless.

Newhart reprises his unforgettable role as Arthur Jeffries from “The Big Bang Theory,” for which he had won an Emmy. In the pilot episode of “Young Sheldon,” we finally get to see Newhart play Professor Proton, the host of a science education show that Sheldon loved in his childhood. And it isn’t the character’s only appearance, either. Each time we see him, Newhart brings his classic straight-faced delivery to a man clearly living a life of quiet desperation. This is one of many callbacks that “Young Sheldon” has made to the “Big Bang Theory,” serving as a nice treat for viewers and providing a connection to the original show.

Given the kind of tough guy, underworld roles Liotta typically played, “Young Sheldon” might’ve been the last place someone would expect him to guest star. However, the “Goodfellas” was perfectly cast as Vincent, a shady bookie whom Connie runs into at a Louisiana casino. Liotta infused the part with the perfect balance of humor and grit, making us laugh while still respecting his imposing presence as he tried to shake down Sheldon’s Meemaw. This appearance gave the late actor a chance to show a side of him audiences often didn’t get to see in a lighthearted family sitcom, and it was great.

A few years after making appearances in shows like “The Simpsons” and “The Big Bang Theory,” Musk showed up in “Young Sheldon”’s first season. In a flash-forward toward the end of the sixth episode, Musk borrows ideas from a notebook that Sheldon worked on when he was young for his SpaceX company. It goes without saying, but getting a tech billionaire and one of the richest men in the world is a big boon for the show. While there’s no denying Musk is a controversial figure, he is at least able to poke fun at himself with this cameo.

Before we unveil our top pick, here are a few honorable mentions.

Billy Gardell as Herschel Sparks, Various
The “Bob Hearts Abishola” Star Is the Salt of the Earth as a Neighbor to the Coopers

Melanie Lynskey as Professor Dora Ericson, "A Philosophy Class and Worms That Can Chase You" & "An Existential Crisis and a Bear That Makes Bubbles"
This Philosophy Professor Leaves Sheldon Flustered

Ming-Na Wen as Dr. Carol Lee, "A Free Scratcher and Feminine Wiles"
Watching Her Outwit Sheldon Never Gets Old

Cyndi Lauper as Herself, "A Baby Tooth and the Egyptian God of Knowledge"
The Singer Makes a Poster Come Alive

David Hasselhoff as Himself, "Cowboy Aerobics and 473 Grease-Free Bolts"
Is There Anything the Hoff Can’t Do?

One great callback “Young Sheldon” has made to “The Big Bang Theory” is having main cast members from the original show on as guest stars. Simon Helberg, for instance, has returned as Howard to notably talk about engineering – what else?! Kaley Cuoco, for her part, showed us what she could do as pool water. However, our favorite of these appearances has to be Mayim Bialik. She once again plays Amy Farrah Fowler, Sheldon’s partner, as we hear her voice in the narration. Her feisty personality is a great contrast to his stubborn attitude, and we love getting tastes of it on “Young Sheldon” just as much as we did on its predecessor.