25 Actors You Didn’t Know Were in These Popular TV Shows
Some of the biggest names in movies and television turned up in small roles on fan-favorite series long before they were household names, or slipped in for one-off cameos that even dedicated viewers missed. These appearances are easy to overlook, especially when they’re tucked into a single episode or a short arc in the middle of a long-running hit.
Here are twenty-five actors whose guest spots and early roles hide in plain sight on shows you probably know by heart. For each entry, you’ll find the character, episode context, and what was happening in the story so you can spot the exact moments the next time you rewatch.
Bryan Cranston – ‘How I Met Your Mother’ (2005–2014)
Cranston appears as Hammond Druthers, Ted’s overbearing former boss at an architecture firm. He shows up in multiple episodes giving Ted grief over designs and office politics, memorably wielding a baseball bat as a desk prop and later trying to lean on Ted for a professional favor.
His scenes revolve around Ted’s career track and the push-pull between ambition and mentorship in the New York firm setting. When Druthers resurfaces later in the series, it’s as a callback to Ted’s early-career growing pains and the fallout from their tense working relationship.
Lady Gaga – ‘The Sopranos’ (1999–2007)
Before the music career took off, she appears as a high school poolside teen in the episode where A.J. and friends break into the school. In the scene, the girls watch from the bleachers as trophies are tossed into the water and laugh at the mischief.
The cameo sits inside a story about A.J.’s drifting behavior and the consequences of suburban rule-breaking. Her character has no lines central to the plot, but the moment is easy to locate during the sequence set at the school pool.
Pedro Pascal – ‘Buffy the Vampire Slayer’ (1997–2003)
Pascal plays Eddie, a freshman who befriends Buffy during her first days on campus. After they connect over feeling out of place, he’s turned by a vampire group that’s targeting new students, which sets up Buffy’s first major fight at college.
The episode uses Eddie to show how the college transition unsettles Buffy’s routine and to introduce a new hunting ground for the show’s villains. His transformation and confrontation with Buffy mark the shift from high school threats to campus dangers.
Amy Adams – ‘Buffy the Vampire Slayer’ (1997–2003)
Adams appears as Beth, a member of Tara’s family who arrives in Sunnydale with relatives to pressure Tara about returning home. Her scenes center on a family dispute that exposes how Tara has been hiding parts of her past from the Scooby Gang.
The plot culminates at a group gathering where the family’s claims are tested and Tara’s status within the friend circle is clarified. Adams’ character functions as a catalyst for revealing Tara’s backstory and reaffirming the group’s loyalty.
Aaron Paul – ‘The X-Files’ (1993–2018)
Paul shows up as David Winkle, a teen mixed up with a skateboard crew and a grisly death that draws in local law enforcement. His scenes appear in an investigation that takes Mulder and Scully into high-school hangouts and a science-class mystery with dangerous insects.
The episode frames David as part of a string of incidents that point to an unusual biological culprit. His involvement helps move the case from prank-gone-wrong assumptions to a pattern Mulder and Scully can track.
Brie Larson – ‘Community’ (2009–2015)
Larson plays Rachel, the coat-check attendant who becomes Abed’s girlfriend. She appears across a handful of episodes where their relationship grows through shared pop-culture routines and low-key campus hangouts.
Her scenes often take place at Greendale events or in quick tag sequences that chart small but meaningful steps in Abed’s social life. Rachel’s presence provides a consistent touchpoint for his character development during those seasons.
Tom Hanks – ‘Happy Days’ (1974–1984)
Hanks guest stars as a former classmate who returns to settle an old score with Fonzie. He confronts Fonzie in a dojo and later at Arnold’s, using martial arts bravado to demand a public showdown.
The episode positions the grudge as a comic obstacle that Fonzie must defuse without losing face. The encounter moves through escalating challenges before resolving in a way that preserves the show’s light tone and neighborhood camaraderie.
George Clooney – ‘The Golden Girls’ (1985–1992)
Clooney appears as a young detective investigating a burglary at the ladies’ house. He teams up with a partner, sets up surveillance, and coordinates with Dorothy and Rose as they try to help without derailing the case.
The story thread uses the investigation to put the household in contact with law enforcement and to stage a stakeout sequence. Clooney’s character tracks leads that eventually point to the culprits operating nearby.
Ryan Reynolds – ‘The X-Files’ (1993–2018)
Reynolds plays a high-school jock who becomes a casualty in a case tied to a strange astrological alignment. His character’s fate in the cold-open sets the tone for the episode’s chain of eerie events.
Mulder and Scully follow witness accounts through locker rooms and suburban streets to map out what’s driving the violence. The early death of Reynolds’ character establishes the stakes that carry the investigation forward.
Regina King – ‘The Big Bang Theory’ (2007–2019)
King recurs as Janine Davis, the university’s human resources administrator. She handles complaints about faculty behavior, calls meetings with Sheldon, and later appears in storylines involving grants and workplace procedures.
Her office scenes center on policy enforcement and conflict resolution among the main characters. Janine’s interventions often lead to formal agreements or mandated training that reset the group’s dynamics at work.
Steven Yeun – ‘The Big Bang Theory’ (2007–2019)
Yeun shows up in a flashback as one of Sheldon’s former roommates. In a quick door-answering scene, he warns about the intensity of Sheldon’s rules and the hazards of ignoring the bathroom schedule.
The appearance anchors a backstory sequence that explains how the roommate agreement came to exist. It frames Leonard’s first day with Sheldon and sets up the apartment rules that define the series.
Lin-Manuel Miranda – ‘How I Met Your Mother’ (2005–2014)
Miranda appears on a subway car, trading rhymes with Marshall while a bedtime tale gets delivered in verse. The scene links multiple mini-stories with clean transitions that fit the episode’s all-rhyming structure.
His role supports the musical narrative device by providing rhythm and call-and-response lines. The segment is easy to spot because it’s staged entirely on the train with riders reacting to the performance.
Donald Glover – ‘Girls’ (2012–2017)
Glover plays Sandy, a guy Hannah dates during the early run of the show’s New York stories. Their scenes include apartment conversations and a breakup that follows an argument about Hannah’s writing and his politics.
The arc uses their relationship to explore conflicting views on art, ambition, and social issues. Sandy’s exit marks a pivot point in Hannah’s dating life and creative choices.
Kate Winslet – ‘Extras’ (2005–2007)
Winslet appears as herself, filming a movie within the show while sharing advice between takes. She leans into awards talk and gives off-camera pointers to the lead character during phone-based gags.
Her cameo drives a set of on-set misunderstandings and makes space for the show’s recurring theme of fame colliding with everyday awkwardness. The scenes intercut rehearsal, costume, and break moments to land the jokes.
Daniel Radcliffe – ‘Extras’ (2005–2007)
Radcliffe plays a heightened version of himself visiting a set and trying to impress older colleagues. He carries around a prop packet that becomes a running joke and awkwardly strikes up conversations that go off the rails.
The episode builds his bits into the day’s production chaos, with crew members trying to manage appearances and press. His character’s behavior pushes the main cast into damage control as the shoot unravels.
Emilia Clarke – ‘Futurama’ (1999–2013)
Clarke voices Marianne, a flower-shop worker who starts dating Dr. Zoidberg. The story reveals that she cannot smell, which makes Zoidberg’s natural odor a nonissue and allows the relationship to blossom.
The episode follows their dates through New New York locations and a medical twist that threatens their connection. Her character’s condition becomes central to a decision Zoidberg must make late in the story.
Paul Rudd – ‘Friends’ (1994–2004)
Rudd plays Mike Hannigan, who meets Phoebe after a blind-date mix-up. He returns for multiple episodes, joins group gatherings at Central Perk and the apartment, and builds a steady relationship with Phoebe.
His arc includes a trip storyline, an engagement, and a wedding that ties into the series’ closing stretch. Mike’s piano background surfaces in several scenes that round out his character profile.
Brad Pitt – ‘Friends’ (1994–2004)
Pitt guest stars as Will Colbert, a former classmate of Ross and Monica who visits for Thanksgiving. He reveals membership in a high-school club that targeted Rachel, sparking a dinner table blowup.
The episode weaves Will’s old grudges into the holiday chaos, with past school rumors colliding with present-day relationships. His presence drives the meal’s running gags and the confession chain that follows.
Gabrielle Union – ‘Friends’ (1994–2004)
Union appears as Kristen, a woman who dates Joey and Ross in quick succession without knowing they’re friends. The situation leads to a street-corner standoff where both men try competing invitations.
Her scenes connect to a scheduling farce that hinges on apartment visits and hallway encounters. The resolution comes when the truth surfaces and the double-booking collapses.
Dwayne Johnson – ‘That ’70s Show’ (1998–2006)
Johnson plays wrestler Rocky Johnson in an episode built around a live event the gang attends. He appears backstage and in ring-side moments that reference the wrestling world of the era.
The cameo drops the characters into a sports-entertainment setting and uses period details to sell the venue and crowd. It’s framed as a special outing that gives the group a break from Point Place routines.
Jensen Ackles – ‘Smallville’ (2001–2011)
Ackles joins as Jason Teague, who dates Lana and works as an assistant football coach at the high school. His family ties introduce a new set of antagonists with interests in the town’s mysteries.
The arc places him in locker rooms, classrooms, and Luthor-connected plots that overlap with Clark’s investigations. His storyline threads through romantic complications and secret-society intrigue.
Adam Scott – ‘Veronica Mars’ (2004–2007)
Scott plays Mr. Rooks, a popular teacher accused of misconduct. Veronica takes the case, gathering statements from classmates and tracking down evidence that shifts suspicion multiple times.
The episode structures the investigation around interviews, classroom scenes, and a final-act reveal. Mr. Rooks’ role sits at the center of the case file that Veronica assembles.
Tessa Thompson – ‘Veronica Mars’ (2004–2007)
Thompson appears as Jackie Cook, the daughter of a pro baseball player who starts dating Wallace. Her arrival stirs tension at school and pulls Wallace into situations that complicate his friendship with Veronica.
Across her episodes, Jackie confronts rumors, family baggage, and a public-image problem. The arc ties into side cases and school events that intersect with Veronica’s main mysteries.
Chris Pratt – ‘The O.C.’ (2003–2007)
Pratt plays Ché, an eccentric campus activist who befriends Summer during her time away at college. He organizes protests, hosts woodland retreats, and pops up with environmental stunts that disrupt class life.
His appearance shifts the setting from Newport to university storylines and gives Summer a new social circle. Ché’s antics set off plots involving student government and campus security.
Benedict Cumberbatch – ‘The Simpsons’ (1989– )
Cumberbatch provides guest voices in a London-set episode, including a prime minister and a wizarding-school send-up during a cutaway gag. His lines land during quick-hit scenes that move the family through famous landmarks.
The cameo supports a travel plot that stacks parodies and celebrity voices. His roles are easy to spot in the segments that mention government offices and a classroom with cloaked students.
Share your favorite surprise appearances in the comments so everyone can queue up the exact episodes and compare notes.
