She played Galinda, later known as Glinda, in Wicked; fellow actress Melissa Fahn was her understudy. She also won a Tony Award for her role of Sally is You're a Good Man Charlie Brown. Other Broadway credits include Precious McGuire in Steel Pier, Louise Goldman in Epic Proportions, Eve, Barbara, Passionella, and Ella in The Apple Tree, Fran Kubelik in Promises, Promises, and Lily Garland in On the Twentieth Century.
For Disney, she portrayed Lily St. Regis in the 1999 Disney television film adaption of Annie, and later went on to portray Marian Paroo in Disney's television adaption of The Music Man in 2003. She provided the voice of Rosetta in Disney's 2008 film, Tinker Bell and some of its sequels. She also voiced the Sugar Plum Fairy in the animated film, Strange Magic in 2015. She also played Georgia King in the 2010 Touchstone Pictures film You Again. Additionally, she portrayed Maleficent in the Disney Channel Original Movie, Descendants. She also voiced Museum Guide in Fillmore!, and portrayed Diane in the ABC TV show Ugly Betty and Carlene Cockburn in the ABC TV show GCB. She appeared in the The Muppets episode "The Ex-Factor".
- Kristin has played Dove Cameron's mother twice, in two different roles. The first being Maleficent in Disney's Descendants and the second role being Velma Von Tussel in NBC's Hairspray Live!
- She is the third person to portray a live-action version of Maleficent, after Kristin Bauer van Straten in Once Upon a Time and Angelina Jolie in the 2014 movie.
- Chenoweth was also originally going to provide the speaking and singing voice of Rapunzel in Disney's animated film Tangled, but was soon replaced by Mandy Moore, due to scheduling conflicts.