Some of these are completely out of the blue...
Taylor Swift made a surprising cameo on New Girl as Elaine, a guest at Cece and Shivrang's wedding, in Season 2's finale. She appears near the end of the episode, where she declares her love for him. Swift's cameo is short but perfectly suited to the show's chaotic comedy. Many Swifties believe that her appearance in the TV sitcom is a direct reference to her 2010 album titled "Speak Now". | © 20th Century Fox Television
Before becoming one of Hollywood's biggest movie stars, George Clooney was already famous for playing Dr. Doug Ross on ER. His cameo in Season 1, Episode 17 of Friends capitalized on that fame by having Clooney appear as Dr. Michael Mitchell, an attractive doctor treating Rachel after she injures her ankle. Interestingly, Noah Wyle also appeared alongside him, making the episode a mini-ER reunion. | © Warner Bros. Television
Jack Black showed up in Season 1, Episode 13 of Community as Buddy, a student who attempts to join the study group. His character's exaggerated confidence and bizarre behavior were hysterical. Many suspect that Black's unexpected cameo in the sitcom is due to his longstanding relationship with Dan Harmon, the creator of Community. | © Universal Television / Sony Pictures Television
Jennifer Aniston made a surprisingly wild appearance in Season 3 of 30 Rock as Claire Harper, an unstable former friend of Liz Lemon. Rather than simply playing herself, Aniston portrayed a woman whose infatuation with Liz and Jack Donaghy spirals into a stalker-like obsession. It was completely unhinged, and we love Aniston for that. | © Universal Television
Brad Pitt made one of Friends' most memorable celebrity appearances when he played Will Colbert, Ross' former high school classmate, in Episode 9 of Season 8. The twist was that Will absolutely hated Rachel. He and Ross were actually co-founders of the "I Hate Rachel Green Club" in high school. Pitt's appearance was especially amusing because he was married to Jennifer Aniston at the time, which made his character even more incredible. | © Warner Bros. Television
Robin Williams took on a interesting role in Law & Order: Special Victims Unit by playing Merritt Rook in Episode 17 of Season 9. Rather than appearing as a comedic version of himself, Williams portrayed a troubled audio engineer who becomes involved in an elaborate psychological scheme. Mariska Hargitay later shared that Williams was the show's "most memorable cameo". | © Universal Television / Wolf Entertainment
Zooey Deschanel made a special cameo appearance on Brooklyn Nine-Nine as part of a crossover event with New Girl. She played the role of Jessica Day, her character from New Girl. In the episode, Detective Jake Peralta frantically commandeers an SUV driven by Deschanel, who is visiting New York from Los Angeles. | © Universal Television / Femulon
Curb Your Enthusiasm is no stranger to having a cameo or guest star in its episodes. However, Bryan Cranston's appearance as Larry's passive-aggressive therapist is just too hilarious not to mention. Cranston's performance stands out because his calm professional persona clashes with Larry's inability to stop creating social disasters. It was a fun cameo, considering that Cranston is famously known for his serious role as Walter White in Breaking Bad. | © HBO Entertainment
Kim Kardashian made a brief appearance as herself on 2 Broke Girls in the show's fourth season. She appears in a storyline involving Max and Caroline's cupcake business, with the pair hoping to capitalize on Kardashian's celebrity status. In this episode, she unexpectedly shows up at their shop, buys a cupcake, leaves a large tip, and promises to shout out their brand on her social media. | © Michael Patrick King Productions / Warner Bros. Television
Amy Adams appeared in The Office as Katy, an attractive purse salesperson. Her role was relatively small, but her involvement is now a fun bit of trivia considering how much of a superstar she has become after her cameo. She made an appearance in this role for three episodes, making her one of the show's more notable early guest stars. | © Universal Television
Amy Poehler appeared on Arrested Development as Gob Bluth's unnamed on-again, off-again wife. She appeared in five separate episodes in this role, in which she was simply known as "Wife of Gob". At the time of her appearance, Amy Poehler and Will Arnett were married in real life. | © 20th Century Fox Television
Michelle Obama made a memorable appearance as herself in the Season 6 finale of Parks and Recreation, where she turns up during Leslie Knope's final adventures in Pawnee. Her cameo was surprising because the show managed to bring an actual former first lady into its fictional small-town world without making the moment feel completely out of place. Michelle Obama previously made cameos in other TV shows, such as iCarly and Nashville. | © Universal Television / Femulon / Deedle-Dee Productions
Britney Spears appeared on How I Met Your Mother as Abby, an obsessive receptionist at Ted's workplace who develops a crush on him. She appeared in two episodes during Season 3, where she was part of a storyline involving Barney and Ted. It's certainly one of the more unbelievable cameos out there in modern TV. | © 20th Century Fox Television
Elon Musk made a cameo on The Big Bang Theory in Season 9, Episode 9, where he appears as himself during a Thanksgiving storyline. Howard encounters Musk while volunteering at a soup kitchen, where the billionaire is helping serve meals. The episode ends with the two of them sharing a leftover piece of pumpkin pie. | © Chuck Lorre Productions / Warner Bros. Television
Ed Sheeran made a short cameo during the season seven premiere of Game of Thrones, playing a Lannister soldier named Eddie. He is introduced while singing around a campfire with fellow soldiers before briefly interacting with Arya Stark. Sheeran's appearance generated plenty of attention not only because it was so out of pocket, but also because he was one of the world's biggest musicians at the time. | © HBO Entertainment
The biggest surprise on a TV show isn't always a major plot twist. Sometimes, it's a familiar face suddenly showing up on screen. That said, these 15 celebrity cameos on popular TV shows definitely caught viewers by surprise.
