Kenneth Wheeler known as Flex Wheeler, is a former American IFBB professional bodybuilder. Wheeler was described by Arnold Schwarzenegger as one of the greatest bodybuilders he ever saw.

After a short career as a police officer, Wheeler focused full-time on becoming a professional bodybuilder. He competed for the first time in 1983 but it was not until 1989 that he secured a first-place trophy at the NPC Mr. California Championships. He placed second at the 1993 Mr. Olympia, narrowly missing a win (something he was to repeat in 1998 and 1999). He is a 5-time Ironman Pro winner, 4-time Arnold Classic winner, and has won the France Grand Prix, South Beach Pro Invitational, Night of Champions and Hungarian Grand Prix.

While Wheeler had the reputation of being arrogant and overconfident. He attributed this to a need to compensate for his introversion and insecurity as a child and young man.

 In 1994, he was involved in a near-fatal car accident that could have left him with lifelong paralysis. Falling back into depression again, he started training from scratch, returning with remarkable speed to bodybuilding's top tier. In 1999, Wheeler discovered that he had Focal segmental glomerulosclerosis, a form of kidney disease. Despite press speculation as to the cause of the failure, Wheeler pointed out that the condition is hereditary, not self-inflicted. Wheeler announced his retirement from competitive bodybuilding in 2000, but continued to compete until 2002. He received a kidney transplant in 2003.