Bell was born and raised in Huntington Woods, Michigan, a suburb of Detroit. She is the daughter of Tom Bell, a television news director, and Lorelei "Lori" Bell, a registered nurse. Bell is of Polish and Scottish descent. Her parents divorced when she was two years old, and she has two half sisters, Sara and Jody, from her father's second marriage. Bell has a lazy eye which affects her right eye. She inherited it from her mother, who had it corrected as a child. Bell claims that if she does not get enough sleep, it furthers the ailment. She nicknames her right eye "Wonky".
At the age of four, Bell claimed she did not like her first name and opted to change it to "Smurfette" after the character in the The Smurfs however, her mother convinced Bell to go by her middle name of Anne instead; she used the name Annie until high school. She attended Burton Elementary school in Huntington Woods where she studied singing and tap dancing.
Just before her freshman year of high school, Bell's parents decided to pull her from the public school system. She then attended Shrine Catholic High School in nearby Royal Oak, where she took part in the drama and music club. During her time at the school, she won the starring role in the school's 1997 production of The Wizard of Oz as Dorothy Gale and also appeared in productions of Fiddler on the Roof (1995), Lady Be Good (1996), and Li'l Abner (1998). In 1998, the year she graduated, Bell was named the yearbook's "Best Looking Girl" by senior class vote.
When Bell was 17, her best friend Jenny DeRita, whom she met at age 11 during a Detroit community theater production, was killed in an automobile accident. Bell said that it was "both the best and worst thing that has ever happened to me. [...] Once you learn not to take people for granted, you live a lot happier life."
Shortly after her high school graduation, Bell moved to New York and attended the Tisch School of the Arts at New York University, majoring in musical theater. In 2001, during her senior year at New York University, Bell left a few credits shy of graduating to take a role in the Broadway musical version of The Adventures of Tom Sawyer.
In 1992, Bell went to her first audition and won a dual role as a banana and a tree in a suburban Detroit theater's production of Raggedy Ann and Andy. Her mother had established her with an agent before Bell was 13, which allowed her to appear in newspaper advertisements for several Detroit retailers and television commercials. She also began private acting lessons. In 1998, she appeared with an uncredited role in the locally filmed movie Polish Wedding.
In 2001, Bell left New York University to take a key role as Becky Thatcher in the short-lived Broadway musical of The Adventures of Tom Sawyer. That same year she made her credited film debut in Pootie Tang. However, her one line in the film was cut and her appearance exists only as a scene shown during the credit sequence. Additionally, she auditioned for the television series Smallville for the role of Chloe Sullivan, a part eventually won by Allison Mack. In 2002, she appeared in the Broadway revival of The Crucible with Liam Neeson, Angela Bettis and Laura Linney. Bell then moved to Los Angeles, California in 2002 because of her friendship with writers Kevin Murphy and Dan Studney, and appeared in a handful of television shows as a special guest, finding trouble gaining a recurring role in a television series. Bell had "tested like eight times and booked nothing and every show [she] tested for got picked up," including auditions for Skin and a Norm Macdonald series. In 2003, she landed a role in the Hallmark Channel movie The King and Queen of Moonlight Bay.
In 2004, Bell appeared in the Lifetime television movie Gracie's Choice, which received one of the network's highest ratings. She made her debut in a theatrically released film, with David Mamet's Spartan, as Laura Newton, the kidnapped daughter of a high-ranking U.S. government official, acting alongside Val Kilmer. Bell also guest-starred on the HBO's drama Deadwood in a two-episode story arc ("Bullock Returns to the Camp" and "Suffer the Little Children").
She then won the role of the title character in UPN's drama Veronica Mars, which was launched in the fall of 2004. Created by Rob Thomas, Bell starred as the seventeen year old detective Veronica, which put her alongside actors Enrico Colantoni who played her father, Jason Dohring, Percy Daggs III and Ryan Hansen. Veronica Mars was described as "a little bit Buffy and a little bit Bogart." Bell noted the parallels between the character of Veronica and her own life - Bell's parents had divorced and her best friend had also died, like that of Veronica. The series earned positive reviews from television critics, as did Bell's performance. Some critics felt that she was overlooked, however, and deserved an Emmy Award nomination. As a writer at the tvaddict.com commented, "[Bell's] complete lack of Emmy recognition proves that voters don’t actually watch the tapes before they vote."
In 2005, Bell starred in Reefer Madness: The Movie Musical, reprising the role she played in the short-lived 2001 off-broadway musical. The musical was a spoof of the 1936 exploitation film of the same name. Reefer Madness: The Movie Musical debuted on the Showtime network on April 16, 2005. On September 18, 2005, Bell performed the theme song from Fame on the "Emmy Idol" portion of the 57th Annual Primetime Emmy Awards. She and the cast of Veronica Mars were nominated for two Teen Choice Awards in 2005: "Choice Breakout Actress" and "Choice Breakout TV Show".
In 2006, Bell won the Saturn Award for "Best Actress on Television" for her acting on Veronica Mars, while the series was nominated for "Best Network Television Show". Aside from working on Veronica Mars, in April Bell starred as Gracie in Fifty Pills, an entry for the Tribeca Film Festival. She appeared in a short independent film called The Receipt and the horror film Roman, which was directed by her The Crucible co-star Angela Bettis. Released on August 11, 2006, Pulse starred Bell as the lead Mattie. A remake of the Japanese horror film Kairo, the film grossed $27.9 million worldwide, however it garnered negative response from critics. Frank Scheck of The Hollywood Reporter commented, "despite the starring presence of Kristen Bell, [the] young actress has far less interesting material to work with here than she does as [the character] "Veronica Mars.""
Veronica Mars continued on UPN until the third season, in which the show was renewed and returned on the newly created The CW. On January 19, 2007 CW Entertainment President Dawn Ostroff announced that, while she was pleased with the gradual improvement of Veronica Mars's ratings, the series would be put on hiatus after February sweeps to air a new reality series, Pussycat Dolls Present. On May 17, 2007 Ostroff announced the cancellation of the series. The two-hour series finale aired in the United States on May 22, 2007, and on June 11, 2007 Thomas officially announced in an email to TV Guide's Michael Ausiello that Veronica Mars had been canceled by the CW. A Veronica Mars feature film and comic book series continuation had been discussed, and for a short time there was talk of another collaboration between Bell and creator Thomas that would be unrelated to the Veronica Mars series.
Following the cancellation of Veronica Mars, Bell had voiced interest in appearing on Heroes because she was a fan previous to being cast. On July 29, 2007, during a train ride back to Los Angeles from the San Diego Comic-Con with Heroes actors Zachary Quinto and Masi Oka, and writers from the series, the writers had mentioned that if she "ever want[ed] to come on Heroes, give us [writers] a call", to which Bell said she would love to. She was also spoken to about a role on Lost, but was not offered one despite speculation that she was to portray Charlotte Staples Lewis. Announced in August 2007, Bell was to portray Elle Bishop, a "mysterious young lady" with an "awesome power". She did not have to audition for the role of Elle, who made her first appearance in an October 2007 episode, and will appear in at least thirteen episodes during the run of the series. The casting of Bell, as Heroes creator Tim Kring explains, "was not easy to pull off", but because of the large ensemble cast of the series and multiple story arcs, "we found a way to jump into a small window in [Bell’s] schedule." Concurrently with filming on Heroes, she narrates as title character in the CW series Gossip Girl.
Shortly after the cancellation of Veronica Mars in early 2007, Bell filmed on location in Hawaii for her starring role as the title character in the Judd Apatow comedy Forgetting Sarah Marshall. She noted that the improvisational comedy in the film was "a lovely experience". The film, written by and also starring Jason Segel was released theatrically on April 18, 2008. Bell lent her voice and likeness to the video game Assassin's Creed which was released on November 13, 2007 for the PlayStation 3 and Xbox 360 and April 8, 2008 for the PC. In the spring of 2006, she finished filming the Star Wars-themed comedy Fanboys, which recently had its release date pushed to January 14, 2008. This was due to additional funding given to director Kyle Newman to shoot new scenes, however, the busy schedules of the actors only allowed for filming in September 2007, thus moving the release date to accommodate that. Bell will voice the character of Marybelle in the animated feature Sheepish, which also has a 2008 release date. She will also star in the comedy Serious Moonlight, alongside Meg Ryan. The film is in post-production and has an estimated 2009 release date. On March 31, 2008 Bell began shooting for the Mark Steven Johnson-written Disney film When in Rome in locations in Rome and New York. On October 15, 2008, TV Guide reported that Bell has signed on to co-star in Couples Retreat, a comedy chronicling four couples who partake in therapy sessions at a tropical island resort. Jason Bateman will play her husband.
Bell has also said that when she is free from film and television roles, she would like to perform on stage again.