Dexter "The Blade" Jackson is an American retired IFBB Pro League professional bodybuilder and the 2008 Mr. Olympia bodybuilding and 2012 Masters Mr. Olympia champion. With 29 wins, Jackson has the most professional men's bodybuilding titles. He has the distinction of winning the Arnold Classic a record five times. After winning the Arnold Classic in 2015, he placed second in the 2015 Mr. Olympia. He is from Jacksonville, Florida. He retired from professional bodybuilding following the 2020 Mr. Olympia.

Mr. Olympia is the title awarded to the winner of the professional men's bodybuilding contest in the open division at Olympia Fitness & Performance Weekend—an international bodybuilding competition that is held annually and is sanctioned by the IFBB Professional League. Joe Weider created the contest to enable the amateur Mr. Universe winners to continue competing and to earn money. The first Mr. Olympia was held on September 18, 1965, at the Brooklyn Academy of Music, New York City, with Larry Scott winning his first of two straight titles. The equivalent female title is Ms. Olympia.