Carell was raised Roman Catholic and was educated at Nashoba Brooks School, The Fenn School, and Middlesex School. He played ice hockey and lacrosse while in high school. He played the fife, performing with other members of his family, and later joined a reenacting group portraying the 10th (North Lincoln) Regiment of Foot. He attributed his interest in history to this, earning a degree in the subject from Denison University in Granville, Ohio, in 1984.

Carell stated that he worked as a USPS mail carrier in Littleton, Massachusetts, but quit after seven months because his boss told him he was not very good at the job and needed to be faster. Early in his performing career, Carell acted onstage in a touring children’s theater company, later in the comedy musical Knat Scatt Private Eye, and in a television commercial for the restaurant chain Brown’s Chicken in 1989.

In 1991, Carell performed with Chicago troupe The Second City where Stephen Colbert was his understudy for a time. Carell made his film debut in a minor role in Curly Sue. In spring 1996 he was a cast member of The Dana Carvey Show, a short-lived sketch comedy program on ABC. Along with fellow cast member Colbert, Carell provided the voice of Gary, half of The Ambiguously Gay Duo, the Robert Smigel-produced animated short which continued on Saturday Night Live later that year. While the program lasted only seven episodes, The Dana Carvey Show has since been credited with forging Carell’s career. He starred in a few short-lived television series, including Come to Papa and Over the Top. He has made numerous guest appearances, including in “Funny Girl,” an episode of Just Shoot Me! Additional screen credits include Brad Hall’s short-lived situation comedy Watching Ellie (2002–2003) and Woody Allen’s Melinda and Melinda.

On August 5, 1995, Carell married Saturday Night Live alumna Nancy Walls, whom he met when she was a student in an improvisation class he was teaching at Second City. They have two children, Elisabeth Anne “Annie” (born May 2001) and John “Johnny” (born June 2004).

Carell’s first major film role was as weatherman Brick Tamland in the 2004 hit comedy Anchorman: The Legend of Ron Burgundy. Struck by Carell’s performance in the film, Anchorman producer Judd Apatow approached Carell about creating a film together, and Carell told him about an idea he had involving a middle-aged man who is still a virgin. The result was the 2005 film The 40-Year-Old Virgin, which Carell and Apatow developed and wrote together, starring Carell as the title character. The film made $109 million in domestic box office sales and established him as a leading man. It also earned Carell an MTV Movie Award for Best Comedic Performance and a WGA Award nomination, along with Apatow, for Best Original Screenplay.

In 2005, Carell signed a deal with NBC to star in The Office, a remake of the British TV series of the same name. In the series, a mockumentary about life at a mid-sized paper supply company, Carell played the role of Michael Scott, the idiosyncratic regional manager of Dunder Mifflin, in Scranton, Pennsylvania. Although the first season of the adaptation suffered mediocre ratings, NBC renewed it for another season due to the anticipated success of Carell’s film The 40-Year-Old Virgin, and the series subsequently became a ratings success. Carell won a Golden Globe Award and Television Critics Association Award during 2006 for his role in The Office. He received six Primetime Emmy Award nominations for his work in the series (2006–2011). Carell earned approximately US$175,000 per episode of the third season of The Office, twice his salary for the previous two seasons. In an Entertainment Weekly interview, he commented on his salary, saying, “You don’t want people to think you’re a pampered jerk. Salaries can be ridiculous. On the other hand, a lot of people are making a lot of money off of these shows.”

Carell played Uncle Arthur, imitating the camp mannerisms of Paul Lynde’s original character, in Bewitched, a TV adaptation co-starring Nicole Kidman and Will Ferrell. He also voiced Hammy the Squirrel in the 2006 computer-animated film, Over the Hedge and Ned McDodd, the mayor of Whoville, in the 2008 animated film Horton Hears a Who! He starred in Little Miss Sunshine during 2006, as Uncle Frank.

His work in the films Anchorman, The 40-Year-Old Virgin, and Bewitched established Carell as a member of Hollywood’s so-called “Frat Pack,” a group of actors who often appear in films together, that also includes Owen Wilson, Will Ferrell, Vince Vaughn, and Luke Wilson. Carell acted as the title character of Evan Almighty, a sequel to Bruce Almighty, reprising his role as Evan Baxter, now a U.S. Congressman. The film received mostly negative reviews. Carell starred in the 2007 film Dan in Real Life, co-starring Dane Cook and Juliette Binoche.

Carell played Maxwell Smart in the 2008 film Get Smart, an adaptation of the TV series starring Don Adams. It was successful, grossing over $230 million worldwide. During 2007, he was invited to join the Academy of Motion Picture Arts and Sciences. Carell starred with Tina Fey in Date Night during late 2008 and the film was released on April 9, 2010 in the U.S. He voiced Gru, the main character in the Universal CGI film Despicable Me along with Russell Brand, Miranda Cosgrove, and Kristen Wiig. He reprised the role in the 2013 sequel Despicable Me 2 and in the third installment of the film franchise Despicable Me 3 in 2017.

In February 2009, Carell bought the Marshfield Hills General Store in Marshfield, Massachusetts.

Carell was allowed “flex time” during filming to work on theatrical films. Carell worked on Evan Almighty during a production hiatus during the second season of The Office. Production ended during the middle of the fourth season of The Office because of Carell’s and others’ refusal to cross the picket line of the 2007 Writers Guild of America strike. Carell, a WGA member, has written two episodes of The Office: “Casino Night” and “Survivor Man.” Both episodes were praised, and Carell won a Writers Guild of America Award for “Casino Night.” On April 29, 2010, Carell stated he would be leaving the show when his contract expired at the conclusion of the 2010–2011 season because he wanted to focus on his film career. However, according to interviews in The Office: The Untold Story of the Greatest Sitcom of the 2000s, Carell did not actually plan to leave at the time and was only “thinking out loud” during the interview, but after his statement failed to elicit a reaction from NBC, he decided it was best to move on.

His last episode as a main character, “Goodbye, Michael,” aired April 28, 2011, with his final shot showing Carell walking to a Colorado-bound plane to join his fiancée, Holly Flax, in Boulder, Colorado. Although he was invited back for the series finale in 2013, Carell originally declined believing that it would go against his character’s arc. Ultimately Carell did reprise the role briefly in the series finale.

In 2014, Carell starred in the true crime drama film Foxcatcher alongside Mark Ruffalo and Channing Tatum in which Carell played the millionaire and convicted murderer John Eleuthère du Pont. It premiered at the Cannes Film Festival and has received widespread acclaim. Carell was nominated for the Golden Globe for Best Actor and the Academy Award for Best Actor.

Carell played activist Steven Goldstein in the gay rights drama Freeheld, replacing Zach Galifianakis, who dropped out due to scheduling conflicts. The film co-stars Julianne Moore, Ellen Page, and Michael Shannon, and was released in October 2015.

He followed this with another biographical drama, The Big Short, in which he portrayed banker Steve Eisman, whose name was changed in the film to Mark Baum. Directed by Adam McKay, the film stars Christian Bale, Ryan Gosling, and Brad Pitt, and it was released in December 2015. The film also received widespread critical acclaim, earning Carell a Golden Globe Award nomination for Best Actor. The film was also nominated for the Academy Award for Best Picture.

In 2016, he replaced Bruce Willis in Woody Allen’s Café Society (2016), alongside Kristen Stewart and Jesse Eisenberg. The film premiered at the 69th Cannes Film Festival opening the festival. The film is certified fresh with the consensus on Rotten Tomatoes reading, “Café Society’s lovely visuals and charming performances round out a lightweight late-period Allen comedy whose genuine pleasures offset its amiable predictability.”

In addition to working with Carell as a fellow correspondent on The Daily Show, Nancy acted with him on The Office as his realtor and short-lived girlfriend Carol Stills. She also cameoed as a sex therapist in The 40-Year-Old Virgin and played Linda in Seeking a Friend for the End of the World. They also created the TBS comedy series Angie Tribeca starring Rashida Jones, which premiered on January 17, 2016.

For his contributions to the film industry, Carell received the 2,570th star on the Hollywood Walk of Fame in 2016.

In 2017, Carell headlined the biographical comedy-drama Battle of the Sexes, portraying tennis star Bobby Riggs, with Emma Stone co-starring as Billie Jean King. The film received critical acclaim and both Carell and Stone received Golden Globe nominations. Carell also starred as Larry “Doc” Shepherd in the film Last Flag Flying.

In 2018, during the press day for Welcome to Marwen, Carell was asked about participating in a revival of the series. Carell told Collider reporter Christina Radish, “I’ll tell you, no… The show is way more popular now than when it was on the air. I just can’t see it being the same thing, and I think most folks would want it to be the same thing, but it wouldn’t be. Ultimately, I think it’s maybe best to leave well enough alone and just let it exist as what it was…I just wouldn’t want to make the mistake of making a less good version of it. The odds wouldn’t be in its favor, in terms of it recapturing exactly what it was, the first time.”

In 2018, Carell starred in three films. He led the addiction drama Beautiful Boy as real life father David Sheff, whose son Nic (Timothée Chalamet) struggles with drug addiction. He also played Donald Rumsfeld in Adam McKay’s political satire, Vice, about the life of former Vice President Dick Cheney (Christian Bale). The film received mixed reviews, and went on to be nominated for eight Academy Awards, including Best Picture. His third 2018 role was starring as Mark Hogancamp of Marwencol in Robert Zemeckis’ Welcome to Marwen. The film received a 32% on Rotten Tomatoes, with the critical consensus reading, “Welcome to Marwen has dazzling effects and a sadly compelling story, but the movie’s disjointed feel and clumsy screenplay make this invitation easy to decline.” The movie was a box office failure, grossing $12.7 million against a budget of around $49 million.

In 2019, Carell returned to television to star in the Apple TV+ drama series The Morning Show opposite Reese Witherspoon and Jennifer Aniston. Carell played Mitch Kessler, a morning news show anchor who is struggling to maintain relevance after being fired due to a sexual misconduct accusation. The Morning Show received a two-season order from Apple, with the first season premiered in the fall of 2019 and the second season set to premiere in 2020. For his performance in the first season, Carrell was nominated for the Primetime Emmy Award for Outstanding Lead Actor in a Drama Series, his eleventh Emmy nomination overrall. Carrell had originally signed a one-year deal with Apple to star in the first season only but Carrell signed on to star in the second season in October 2019.

Since May 2020, Carrell has also starred in the Netflix workplace comedy series Space Force, based on the proposed space warfare service branch of the United States Armed Forces: the United States Space Force. Carrell created and produces Space Force with Greg Daniels, who created and produced The Office. Carrell also wrote the pilot episode with Daniels. The show was renewed for a second season in November 2020.

Carrell starred in the political comedy film Irresistible, written and directed by Jon Stewart. The film was initially set for a theatrical release in May 2020. Due to the COVID-19 pandemic in the United States, the film was released on Premium VOD and selected theaters on June 26, 2020

In 2020, Carell joined several other Hollywood celebrities in donating money to the Minnesota Freedom Fund (MFF), a nonprofit that “pays bail for those who could not otherwise afford it”.