Hollmann grew up in Fairview Heights, Illinois, where he graduated from Belleville Township High School East in 1981. He won a 2002 Tony Award and a 2001 Obie Award for his music and lyrics to Urinetown. He is a former ensemble member of the Cardiff-Giant Theatre Company in Chicago. He played trombone for the Chicago art rock band Maestro Subgum and the Whole, and also played piano for The Second City national touring company and Chicago City Limits, an improv company in New York City. He attended the musical theatre writing workshop, Making Tuners, at Theatre Building Chicago and the BMI Lehman Engel Musical Theater Workshop in New York. While at the Making Turners workshop he began a show with Chicago-based writer Jack Helbig that became "The Girl, the Grouch, and the Goat," which has had professional productions in Los Angeles and Chicago.
- "2002 Tony Award Winners". New York Times. 2002-01-03. Retrieved 2009-06-07.
- "Wild Goat, from the Creators of Urinetown & Hotel D'Amour Premieres in Chicago January 19". Chicago Pride. 2003-12-19. Retrieved 2009-06-07.
- "PlayBill Biography: Mark Hollmann". Playbill. Archived from the original on 2014-10-22. Retrieved 2009-06-05.
- "Biography of Mark Hollmann". Music Theater International. Retrieved 2009-06-05.