Steve Carell was born in Concord, Massachusetts on August 16, 1963 to an Italian-American family (his original family name was Carello). He was educated at the The Fenn School and Middlesex School in Concord, Massachusetts, as well as Denison University in Granville, Ohio.

He is married to Saturday Night Live alumna and former Daily Show correspondent Nancy Walls, whom he met when she was a student in an improv class he was teaching at The Second City. They have two children, Elisabeth Anne (born May 25, 2001) and John (born June 2004).

Prior to deciding on a career as a performer, he was a mail carrier. He later explained he quit after a few months because he was "very, very bad at it." He also planned on going to law school, but when he was asked on his entry form why he wanted to become a lawyer, he was unable to write a response.

He performed with Chicago troupe The Second City in 1991, where Stephen Colbert was his understudy for a time. That same year, he landed his first film role, a minor one as Tesio in Curly Sue.

In 1996, he was a cast member of the briefly aired The Dana Carvey Show. Along with fellow cast member Colbert, Carell provided the voice of Gary, half of "The Ambiguously Gay Duo." While Carvey was canceled, the Robert Smigel-produced animated short survived, moving to Saturday Night Live in 1997. He played a supporting character in the short-lived 1997 Tim Curry sitcom Over the Top.

Other early screen credits include a role in the short-lived Julia Louis-Dreyfus sitcom Watching Ellie (2002 – 2003) and Woody Allen's Melinda and Melinda.

In 1999, he became a correspondent on The Daily Show, appearing in recurring sketches like "Even Stevphen" (opposite Stephen Colbert), "Slimmin' Down With Steve" and "Produce Pete with Steve Carell". He remained a regular on the show until 2004.

Carell returned to The Daily Show on March 23, 2005, for a piece on the second anniversary of the 2003 invasion of Iraq.

While there, he also recorded two guest appearances as Produce Pete which aired on April 4, 2005, and May 3, 2005 (and was credited as a contributor).

He returned to the show as the guest on August 15, 2005, and declared on that day's program that he was officially no longer with the show, ending a bit of speculation as to whether he would one day return or not.

Two supporting roles in films helped get the attention of audiences: In Bruce Almighty, Carell played Evan Baxter, an arrogant rival to Jim Carrey who gets the ultimate comeuppance at a news desk. In Anchorman: The Legend of Ron Burgundy, he played another news personality, this time as the slow weatherman Brick Tamland, whose non-sequiturs helped make the comedy a success at the box-office..

In spring of 2005, Carell began playing the lead role of Michael Scott on NBC's remake of the British sitcom The Office. Although the series premiered to mediocre ratings, NBC renewed it for a second season due to its success on the iTunes Store, and the show subsequently became a ratings success. Carell won a Golden Globe and Television Critics Association award in 2006 for his Office role. He also received an Emmy nomination in 2006 for his work in the series. He played the lead role in the 2005 film The 40-Year-Old Virgin, which he developed and co-wrote. Although the film was a surprise success, he revealed in an interview with Entertainment Weekly that he has no plans to leave The Office.

Carell currently earns approximately $175,000 per episode of the third season of The Office, twice his salary for the previous two seasons. Carell is also allowed flex time during filming to be able to work on theatrical films. While he was shooting Evan Almighty, Carell shot the film during weekdays and appeared in The Office on weekends for its third season.

Carell appeared as "Uncle Arthur" alongside Nicole Kidman and Will Ferrell in the 2005 remake of Bewitched. He also voiced one of the starring roles in the 2006 computer-animated film Over the Hedge as Hammy the Squirrel. He starred in Little Miss Sunshine in 2006, as Uncle Frank.

His work in films such as Anchorman: The Legend of Ron Burgundy, The 40-Year-Old Virgin, and Bewitched established Carell as a member of Hollywood's Frat Pack group. This set of actors, headlined by Ben Stiller, Jack Black, Will Ferrell, Vince Vaughn, Luke Wilson, and Owen Wilson, has become one of the most profitable forces in modern comedy. Carell acknowledged his membership in this group during the opening monologue of his October 1, 2005 hosting stint of Saturday Night Live.