William G. Klein (born c. 1948) is a retired American businessman and poker player from Laguna Hills, California.

Klein entered the 2015 $111,111 One Drop High Roller and finished as the runner-up receiving a $2,465,522 payout.

[1] Klein donated his entire payout to two charities, the Orangewood Children’s Foundation and The Shea Center for Therapeutic Riding.

[3] In 2010, Klein appeared in Season 7 of Game Show Network's High Stakes Poker.

In 2015, Klein played in the $250,000 Aria Super High Roller cash game where he won a $458,500 pot after hero calling Antonio Esfandiari with J♣ 8♣ on a board of 7♦ 9♦ 8♦ 9♠ 3♥.