Which investor on Shark Tank is nicknamed “Mr. Wonderful”?

Kevin O'Leary is the Shark Tank investor nicknamed “Mr. Wonderful.”

O'Leary is a Canadian businessman, investor, author, and television personality. He became widely known as a panelist on the Canadian business program Dragons' Den before joining the U.S. version of Shark Tank. His direct negotiating style and frequent emphasis on valuation, cash flow, and deal terms helped establish the nickname.

The title is deliberately ironic: O'Leary often presents himself as charmingly tough rather than conventionally warm. He is also commonly called “Wonderful” in abbreviated references to his television persona.

O'Leary is not the same person as Robert Herjavec, another Canadian entrepreneur who appeared on both Dragons' Den and Shark Tank. Daymond John and Mark Cuban are also Sharks, but “Mr. Wonderful” specifically identifies O'Leary.