American Dad first premiered on February 6th, 2005 straight from the brain of Family Guy creator, Seth McFarlane. Since its debut on Fox, American Dad has had 17 seasons and has slowly become a favorite among adult animation fans. Many fans have grown to love the show over the years, with some even claiming it has surpassed Family Guy.
With 300 episodes in its library, American Dad has had several celebrity guests come on to the show. Patrick Stewart is a recurring guest as the voice of Stan's boss, Bullock. Some celebrities are only guests for one-off episodes. In these roles, the celebrity is often the voice of a character that plays a large role in the episode. Although, sometimes the celebrities will voice themselves.
10 Stephen Colbert
Stephen Colbert is a Comedy Central legend and current host of The Late Show on CBS. Colbert provides the voice for Dr. R. Dandliker in the episode "All About Steve." The episode revolves around Stan shunning Steve for being a nerd, only to then need his son's help to catch a cyberterrorist.
Stan goes to the dentist in this episode to get help with his teeth grinding habit. He encounters Colbert's character there and is told by the dentist that he needs braces. To really pile on the irony, Stan is then bullied and called a nerd by the other CIA agents.
9 Craig Ferguson
Host of The Late Late Show, Craig Ferguson, has appeared twice in the show as Evil Barry. Ferguson has the honor of voicing a very interesting character, as Evil Barry is arguably one of the show's greatest antagonists.
In the episode "With Friends Like Steve's" Evil Barry attempts to steal Steve's entire life by having him sent to an oil rig in the Atlantic. Barry transforms into Evil Barry when he stops taking his aggression suppressing pills.
8 Seth Rogen
Seth Rogen is a well-accomplished actor, comedian, and screenwriter. No stranger to voiceover work, Rogen voiced one of the kids at Camp Refoogee in the first episode of season 2.
The entire plot of this episode is that Stan is desperate to send Steve to a summer camp so that he may have the same experiences Stan did as a child. Stan mistakenly sends Steve to a refugee camp by misreading the word as "Refoogee." Steve ends up saving the refugees in the camp from rebels by beating their leader in a foot race.
7 Elizabeth Banks
Elizabeth Banks is an American actress and is best known for her roles in Wet Hot American Summer, The Hunger Games, and many other notable films. Banks voiced both Becky Arangino in "The Vacation Goo" and Lisa Silver in the episodes "1600 Candles" and "Escape From Pearl Bailey."
Both of these characters act as love interests for Steve. Becky meets a horrible end at the hands of the Smith family, while Lisa is a recurring character that goes to high school with Steve.
6 Forest Whitaker
Forest Whitaker is the proud owner of an Academy Award and a Golden Globe. He also voices the first three Turlington Detectives that appear in episodes "Meter Made", "Chimdale", and "Live and Let Fly."
The Turlington Detectives are all detectives in Langley Falls that bear the last name Turlington. They all look identical and they all have the same mannerisms, often referring to their mother for guidance. The later two Turlington detectives are voiced by guest star Craig Robinson.
5 Amanda Seyfried
Amanda Seyfried is well-known for her role in the musical sensation Mamma Mia! and has starred in multiple films throughout her acting career. She played the voice of Amy in the episode "Escape From Pearl Bailey."
Amy's character is a part of a group of high school girls that bully Steve's girlfriend Debbie. To get revenge, Steve gives laxatives to a bull and has it excrete on Amy while she's driving her convertible. Steve's dark path of vengeance in this episode leads to Debbie resenting him in the end.
4 Ken Jeong
Ken Jeong introduced himself to the world through his character Leslie Chow in The Hangover films. He also starred in the ABC sitcom Dr. Ken and is a licensed physician himself. Ken Jeong has been the voice of three different minor characters throughout American Dad.
He first voiced a psychologist in the episode "Family Affair", then appeared as a doctor in "Every Which Way But Lose." His last voice role for American Dad was for the character Butch Johnson, who desperately needs launch codes in the episode "Flirting With Disaster."
3 CeeLo Green
CeeLo Green is a prominent figure in the music industry as a singer, songwriter, record producer, and former judge on The Voice. He has a large presence in the episode "Hot Water." He does the voice for a sentient hot tub, himself, and appears in live-action as the narrator of the episode.
This episode centers around Stan bringing home an evil hot tub that becomes obsessed with him, to the point that it tries to kill him.
2 Tj Miller
Renowned comedian Tj Miller has done a couple of voice roles for American dad, the first coming in season 9 in the episode "Poltergasm" as the voice of Benji. His second voice role was for the cowboy in the hilarious Beer Water commercial seen in the episode "News Glance With Genevieve Vavance."
Perhaps Miller's most famous voice role was for the film Big Hero 6, where Miller voiced Fred, a member of the superhero team in the film.
1 Snoop Dogg
Rapper, actor, and modern-day hero Snoop Dogg has done voiceover work for one character in a recent episode of American Dad. In episode 5 of season 14, Snoop Dogg voices the character Tommie Tokes. Tokes is essentially Willy Wonka with a twist appropriate for Snoop.
In this episode, Jeff wins a contest to tour Tommie Tokes' weed factory, and he chooses Stan to accompany him on the tour. Tommie Tokes fears that Stan may be a narc, so he tries to turn him into a "Snoopa Loompa."