While not playing with the band Trenchmouth, Armisen's interests switched to acting. In a January 2006 interview, he said, "I wanted to be on TV somehow. For some reason, I always thought it would be an indirect route; I didn't know that it would be comedy and Saturday Night Live. I just wanted to do something with performing that would lead me there."
In 2014, Armisen worked as bandleader on Late Night with Seth Meyers received positive reviews for his deadpan comedy, especially in his interplay with the host.
Saturday Night Live
Armisen joined the cast of Saturday Night Live in 2002. He was promoted to a repertory player in 2004. After 11 years as a cast member, he decided to leave the show. At the time of his 2013 departure from the show, Armisen was the third-longest tenured cast member (behind Seth Meyers and Darrell Hammond), and he appeared in the second-most sketches (856) of any cast member. Since then, Armisen has come back for multiple cameo appearances on the show, including when he hosted the season 41 finale on May 21, 2016, with musical guest Courtney Barnett.
The following is a partial list of notable roles Armisen has played in Saturday Night Live sketches.
Billy Smith - a Native American stand-up comedian who tells Native-American-themed jokes that no one understands.
Leonard - the strange European host of the foreign music show Club Traxx.
Mackey - a senile drummer who often does rimshots at inappropriate moments and appears in the "Rialto Grande" sketches.
Nooni Schoener - a quirky, foreign art dealer who appears with his wife Nuni Schoener (played by Maya Rudolph) in "the Schoeners" sketches.
Frondi - a mentally challenged character who criticizes Ben Affleck's movie Gigli to Ben himself.
Manuel Ortiz - host of The Manuel Ortiz show on Television Dominicana where he "helps with whatever it is" his audience members are going through.
Nicholas Fehn - a political commentator whose mind wanders so much that he is incapable of finishing a sentence without starting a new one.
Roger A. Trevanti - a greedy studio head and AMPTP member who rails against the 2007-08 Writers Guild of America strike. The character's only SNL appearance was on the last episode of season 33, before the show went on hiatus for the WGA strike, but he appeared in several Internet videos around the same time.
Roger Brush - a producer of multiple "Dr. Phil"-type talk shows, each focused on a different topic (teen, marital, sexual, and pregnancy issues), who fills in when the hosts are sick. He repeatedly tells guests relating their problems to speak up, and, unable to relate to their problems, offers them either useless advice based on his experience or no help at all.
Garth - part of Garth & Kat (with Kristen Wiig), a musical duo who appear on Weekend Update unprepared and make up songs on the spot.
Giuseppe - the saxophone player for What's Up With That?
Regine - a pretentious and condescending woman who exhibits blatant euphoric and erotic facial expressions when touched on certain parts of her body.
Ian Rubbish - A late-1970s/early-80s British punk rocker, a parody of Sex Pistols' John Lydon, who caught heat from his bandmates Derek Gash (played by Bill Hader) and Keith Grimshaw (played by Taran Killam) and fans for writing and performing songs supporting Conservative Prime Minister Margaret Thatcher.
Armisen's list of notable impressions has included:
Barack Obama - recurring in Season 33 and Season 34 episodes as the Democratic presidential candidate (Season 33), the Democratic nominee, President-elect, and President (Season 34), beginning on February 23, 2008. As of season 38, Jay Pharoah replaced Armisen as Obama.
Prince - parody of the musician as the host of a talk show called The Prince Show, with Beyoncé Knowles (played by Maya Rudolph) as his co-host. Armisen, a fan of Prince since childhood, created the sketch as a way of improving his chances of meeting the musician.
Steve Jobs - Apple CEO who appears on Weekend Update to show off strange new technology. Armisen has stated that Steve Jobs is the celebrity he most enjoys portraying.
Queen Elizabeth II - There were four sketches between the years 2010 and 2012 where he played the Queen of the United Kingdom.
Michael Bloomberg - numerous sketches between 2011 and present, including recurrent segments during the 2020 Democratic Primaries.
In 1998, he posed as a music journalist for the short film Fred Armisen's Guide to Music and South by Southwest. It was filmed by then-girlfriend Sally Timms and featured Armisen's "pranking musicians and industry types" during the South by Southwest festival in Austin, Texas. In various segments he asked self-described "stupid" questions, pretended to be German, and also acted blind. A year later, Armisen starred with alternative rock legend Steve Albini in Chevelle's Point #1 EPK.
Armisen is part of ThunderAnt, a comedy duo with Sleater-Kinney guitarist Carrie Brownstein. The duo specializes in creating comedic short skits often about independent vocations such as one-man shows, feminist bookstores, and bicycle rights activists.
Armisen has directed music videos for bands like The Helio Sequence. Armisen also had a role in the Wilco documentary I Am Trying to Break Your Heart, which featured footage from his stint opening for front man Jeff Tweedy's 2001 solo tour. He also appeared in video segments on Blue Man Group's How to be a Megastar Tour 2.0. Armisen occasionally writes for Pitchfork Media and interviewed Cat Power for that company. Fred appeared as Jens Hannemann on Jimmy Kimmel Live! on October 19, 2007, promoting a 28-minute DVD called Fred Armisen presents Jens Hannemann: "COMPLICATED DRUMMING TECHNIQUE". In 2010, Armisen briefly joined Joanna Newsom's tour for her album Have One on Me as his character Jens Hannemann. On SNL, Armisen often plays musical instruments in sketches, has two recurring characters who are musicians (Mackey the drummer from the Rialto Grande and Ferecito from Showbiz Grande Explosion), or impersonates famous figures in the music world such as Liberace, Phil Spector, Lou Reed, and Prince.
Armisen performed as a singer/drummer/comedic actor in the Blue Man Group's "How to be a Megastar Live!". He played the part of a salesman on TV who advertises for the Megastar Rock Manual. He also drummed in the performance and was a backup singer.
In 2015, Armisen was the recipient of Smithsonian magazine's American Ingenuity Award for Performing Arts.
Armisen was married to English singer and songwriter Sally Timms from 1998 to 2004 and to actress Elisabeth Moss from 2009 to 2011. Moss described their time together as "extremely traumatic and awful and horrible", and said Armisen could be best summed up by the description, "He's so great at doing impersonations. But the greatest impersonation he does is that of a normal person." He dated artist Alice Lancaster who, after their break-up, painted a portrait of him entitled, "Fred Armisen: Portrait of a Sociopath".
"I think I was a terrible husband. I think I'm a terrible boyfriend," Armisen later told Howard Stern, "I feel bad for everyone I've gone out with."