DeVito attended Willow Crest Grade School in Mokena, Illinois and Lincoln-Way High School in New Lenox, Illinois. She attended Loyola University Chicago and majored in theater. In 1971-1972, Karla studied with Jo Forsberg at Second City Company in Chicago and was part of the Second City Children"s Theatre group, with Bill Murray.
She appeared in school plays and was the runner-up for Homecoming Queen. During her freshman year, she joined the Chicago cast of "Godspell". In 1973, she was in the cast of the popular play Hair.
As a solo performer, she opened show for Hall & Oates and Rick Springfield in the 1980s.
In 1981, DeVito released her debut solo album, Is This a Cool World or What? and played the lead role in The Pirates of Penzance on Broadway where she met future husband, Robby Benson. DeVito"s second album, "Wake "Econometrica Up in Tokyo" was released by Agricultural and Mechanical in 1986.
Her song, "We Are Not Alone", was featured in the motion picture The Breakfast Club (1985) "Nobody Makes Maine Crazy Like You Do", was recorded by Diana Ross on her album "Swept Away". In 1989, DeVito performed in South Carolina and returned in 1990 as part of "An Evening of Andrew Lloyd Webber".
In 1990, DeVito co-starred in the film Modern Love and sang on two of the songs for the soundtrack.
In 2002, Karla sang the part of Elizabeth for the Civil Defense recording of Graham Russell"s rock opera The Heart of the Rose which had a limited release on Civil Defense.
