She left Troy High School before graduating (she received her diploma via correspondence courses) to join the national tour of The Will Rogers Follies directed by Tommy Tune.

[13] Foster left Les Misérables to join the ensemble of Thoroughly Modern Millie in its pre-Broadway run at the La Jolla Playhouse.

Original leading lady Kristin Chenoweth landed a television series shortly after rehearsals began and was replaced with Erin Dilly as Millie and Foster as her understudy.

The New York Daily News reviewer said: "newcomer Sutton Foster, who has the pert look, the silver voice and the dazzling legwork to make an extraordinarily winning Millie.

"[17] The Newsday reviewer wrote: "She has a smile that may remind you of Mary Tyler Moore, the gawky comic precision of the young Carol Burnett, the lyricism of a romantic heroine and a smallish but vibrant voice as accurate as it is expressive.

As [Millie], another of New York's prototypical small-town girls with big-city dreams, [Sutton Foster] appears unfazed by the burden of a character created onscreen by Julie Andrews.

"[18] Time Magazine wrote: "she's [Sutton Foster] got the full package: girlish gawkiness and Broadway brass, the legs and the lungs.

In May 2005, Foster co-starred as Jo March opposite Maureen McGovern as Marmee in the musical adaptation of Louisa May Alcott's classic novel Little Women, for which she was nominated for her second Tony Award.

She played Janet van de Graaff, a famous Broadway starlet who opts to forgo a stage career in favor of married life.

[27] In 2007, Foster guest-starred on the children's musical puppet show Johnny and the Sprites[28] and in a three-episode story arc on the HBO sitcom Flight of the Conchords.

[34] In 2010, Foster promoted the album with concert performances in Boston, New York City, Chicago, the Orange County Performing Arts Center in Orange County, California, and Washington, D.C.[35] Foster starred as Nurse Fay Apple in the New York City Center's Encores!

[36] Foster made her Off-Broadway debut in Paul Weitz's comedy Trust with Zach Braff, Bobby Cannavale and Ari Graynor which began previews July 23, 2010, with an official opening August 12, running through September 12, 2010, at Second Stage Theatre.

[37] Foster and Seth Rudetsky participated in the one night only Actors Fund benefit concert version of They're Playing Our Song on August 30, 2010, at the Gerald W. Lynch Theater, John Jay College, New York.

The full cast included Efé, Kaitlyn Davidson, Alex Ellis, Maynard, Matt Loehr, and Jesse Nager, and was directed by Denis Jones.

[38] Foster taught a Spring Semester master class at New York University's Tisch School of the Arts Undergraduate Department of Drama, beginning in January 2010.

She also guest-starred in an episode of the NBC legal drama Law & Order: SVU (opposite comedian Kathy Griffin), which aired on March 3, 2010.

[45] Foster played Reno Sweeney in the Broadway revival of Anything Goes, which began performances on March 10, 2011, at the Stephen Sondheim Theatre and officially opened on April 7, 2011.

[50][51] Foster played the lead role in this short-lived 2012 ABC Family drama, developed by Amy Sherman-Palladino, the creator of Gilmore Girls.

She played former Las Vegas showgirl Michelle, who impulsively marries a man, moves to his small town, and begins teaching ballet lessons at her new mother-in-law's dance studio.

[53] In the spring of 2012, she returned to Ball State, teaching classes, mentoring the interdisciplinary team that wrote the musical The Circus in Winter, and co-directing the Department of Theatre and Dance's Spring 2012 production of The Drowsy Chaperone; she also spoke at commencement and received an Honorary Doctorate of Fine Arts degree for her continued engagement with Ball State students.

[61] She later was cast as the lead character of Liza Miller in the TV Land single-camera comedy-drama pilot Younger, created by Darren Star.

[63][64] Also in 2016, Foster played the role of Violet in the miniseries Gilmore Girls: A Year in the Life opposite her ex-husband, Christian Borle.

[78][79] In October 2021, she published a memoir, Hooked, in which she opens up about how she used crafts, specifically cross-stitching, collaging and crocheting, to get through significantly challenging milestones in her life.

[80] In December 2021, she returned to Broadway, starring as Marian Paroo opposite Hugh Jackman as Harold Hill in a revival of The Music Man.

[86] In February 2024, she replaced Annaleigh Ashford in the Broadway revival of Sweeney Todd: The Demon Barber of Fleet Street as Mrs. Lovett.