Mr. Gans had been performing at Wynn Resorts since February. He spent eight years prior at The Mirage.
In a statement Scott Sibella, president of The Mirage, said, "All of us in The Mirage family are deeply saddened to learn of Danny's passing. We all knew of his devotion to his family and our hearts and prayers are with his wife and children."
Steve Wynn, chief executive of Wynn Resorts, said in a statement that Mr. Gans' death was "a profoundly tragic event that leaves us all sad and speechless." He added, "All of us ... are devastated at the loss of our brilliant, talented and loving friend."
Mr. Gans made a brief Broadway appearance in 1995, playing the Neil Simon Theatre Nov. 8-12 in Danny Gans on Broadway: The Man of Many Voices.
He was known for his rapid-fire imitations of Tony Bennett, Al Pacino, Sarah Vaughan, Bill Cosby, Woody Allen and Bruce Springsteen.
Mr. Gans is survived by his wife Julie and his children, Amy, Andrew and Emily.