Directed and choreographed by Denis Jones, performances will continue through June 23.

O'Hurley will play the role of King Arthur. He debuted at The Muny in the 1986 production of Gentlemen Prefer Blondes. The singing actor is best known for his role as J. Peterman on "Seinfeld."

"We're so thrilled to have John lead our season opener," said Muny executive producer Mike Isaacson in a statement. "He's a true renaissance man, as a performer and a person, and his performance of Arthur is sure to thrill the Muny audience."

Based on the 1975 film “Monty Python and the Holy Grail,” Spamalot has a book by Eric Idle and music by John Du Prez. The musical, according to press notes, "tells the legendary tale of King Arthur and his Knights of the Round Table, and raises silliness to an art form." Monty Python’s Spamalot is the winner of three Tony Awards including Best Musical.

The Muny production features scenic design by Sam and Steve Gilliam, sound design by Jason Krueger, lighting design by Seth Jackson and costume design by Leon Dobkowski. Ben Whiteley serves as the musical director, and the production stage manager is Nevin Hedley.

Additional casting will be announced at a later time.

To purchase season tickets by phone, call (314) 361-1900, extension 550, or order online at www.muny.org.