In 1983, he debuted on Broadway, playing opposite Anthony Quinn in Zorba. McCarthy played Bob Freelander in Marvin Hamlisch and Howard Ashman's ill-fated Smile, which opened on Broadway in November 1986. He played Terry in the original Broadway cast of Side Show in 1997, recorded for Sony Music. He is perhaps best known in the theater for his creation of Officer Lockstock in the Broadway production of Urinetown, which opened on Broadway in September 2001. From 1995 - 97, McCarthy played the "Beast" in the Broadway production of Beauty and the Beast . He played Dubhdara in the musical The Pirate Queen which opened on Broadway in April 2007. In 2008, 2009 and 2011, McCarthy played Billy Flynn in Chicago, the long-running Broadway revival. McCarthy created the role of Lola Cola in the premiere of the bluegrass musical, Southern Comfort which opened at the Off-Broadway Public Theater in March 2016.