William Mills "Bill" Irwin (born April 11, 1950) is an American actor and clown noted for his contribution to the renaissance of American circus during the 1970s. He is known for his vaudeville-style stage performances, and has also made a number of appearances on film and television and won a Tony Award for his role in Who's Afraid of Virginia Woolf on Broadway. He is known by children as Mr. Noodle on Sesame Street's Elmo's World.