Norbert Leo Butz (born January 30, 1967) is an American actor and singer known for his work in Broadway theatre. He is a two-time recipient of the Tony Award for Best Actor in a Musical for his performances in Dirty Rotten Scoundrels and Catch Me If You Can, and is one of only nine actors ever to have won the award twice.

Norbert Leo Butz was born on January 30, 1967, in St. Louis, Missouri, the son of Elaine (née Bourisaw) and Norbert Butz. He was raised in a middle-class family; his parents are devout Catholics. He is the seventh of 11 children and is named after his father. Some of his first theatre roles included playing the male leads at local all-girl high schools, such as Cor Jesu Academy and Nerinx Hall. He graduated from Bishop DuBourg High School. Butz earned a Bachelor of Fine Arts from The Conservatory of Theatre Arts at Webster University and a Master of Fine Arts from The University of Alabama/Alabama Shakespeare Festival's Professional Actor Training Program. He would later receive an honorary degree from Webster University in 2013.

Butz made his Broadway debut as a replacement swing – a type of understudy – in Rent in 1996. Butz ultimately replaced Adam Pascal as Roger Davis in 1997. Additional Broadway credits include Thou Shalt Not (Camille Raquin, 2001–2002), for which he received a nomination for the Tony Award for Best Featured Actor in a Musical at the 56th Tony Awards; Wicked (the original Fiyero, 2003); and Dirty Rotten Scoundrels (Freddy Benson) for which he received the Tony Award for Best Actor in a Musical at the 59th Tony Awards, the Drama Desk Award for Outstanding Actor in a Musical, a Drama League Distinguished Performance Award, and an Outer Critics Circle Award. His Off-Broadway credits include The Last Five Years (Jamie Wellerstein), Saved (Fred), and Juno and the Paycock (Jerry Devine), and he has toured as the Emcee in Cabaret and as Freddy in Dirty Rotten Scoundrels.

Butz's film roles have included Went to Coney Island on a Mission from God... Be Back by Five (Pawnbroker), Noon Blue Apples (Howard Philips), and West of Here (Josiah Blackwell).

Butz's projects include the film Dan in Real Life (with Steve Carell, Juliette Binoche, and Dane Cook), released in October 2007, the world premiere of Is He Dead?, a hitherto unproduced Mark Twain play that opened at Broadway's Lyceum Theatre on December 9, 2007, and Fifty Words Off-Broadway with Elizebeth Marvel at the Lucille Lortel Theatre (2008). In January 2008, he appeared as Captain Richard King in the miniseries adaptation of the Lonesome Dove prequel, Comanche Moon.

Starting December 23, 2008, Butz stepped in to replace Jeremy Piven in David Mamet's Speed-the-Plow; Piven suddenly and unexpectedly dropped out of the play after he experienced health problems. Butz took over the part until January 13, 2009, when William H. Macy assumed the role for the remainder of the play's run.

Butz taught at Drew University in Madison, New Jersey, for the spring semester in 2008 in the drama department.

He starred as Rowdy Kaiser in the ABC show The Deep End.