[5] In 1975, Zenk moved to New York City and made her stage debut as well began screen tests for Indiana Jones, Grease, and Superman.
[7] In 1993, Zenk went to star along with fellow daytime performers Deidre Hall and Leslie Charleson in the leading roles of the NBC made-for-television movie Women on the Ledge.
After auditioning for several soap operas, including The Edge of Night, Guiding Light and Search for Tomorrow, Zenk was signed to a contract at As the World Turns and assumed the role of Barbara in 1978.
[9] In the early years of Zenk's run on As the World Turns, her character, Barbara, was tormented by her criminal ex-husband, James Stenbeck (played by Anthony Herrera).
Sheffer was quoted in a 2006 interview in a cover-feature article in The New Yorker that he wanted to give Zenk, who he felt was an "under-utilized gem of an actress", more to do than just pour coffee with children underfoot.
Due to overwhelming audience response, she was asked to reprise the role that fall at the Bucks County Playhouse in New Hope, Pennsylvania.
[citation needed] In June 2007, three weeks after her initial three surgeries for oral cancer, in the 50th anniversary production at Little Theatre on the Square of Sullivan, Illinois.
Recovering from tongue reconstruction and on heavy pain medication due to radiation burning and side effects, Zenk sang and danced with the 35-piece orchestra, and brought down the house.
[citation needed] In April 2011, only four months after more cancer surgery to her tongue, she debuted her one-woman show Colleen Zenk: LIVE at Bob Egan's New Hope, to great critical acclaim.
In late 2012, she starred in the off-Broadway world premiere of the stage version of the bestselling memoir, Marrying George Clooney, Confessions from a Mid-life Crisis.
[citation needed] In 2020, Zenk made several appearances on the YouTube show The Locher Room, which facilitates discussions with entertainment figures, including actors, writers and producers from soap operas.
In 2023, Zenk was cast in a recurring role as Jordan Howard on the CBS daytime soap opera, The Young and the Restless.