Randall Duane Couture (; born June 22, 1963) is an American actor, former U.S. Army sergeant, former mixed martial artist and former collegiate and Greco-Roman wrestler. During his tenures in the Ultimate Fighting Championship (UFC), he became a three-time UFC Heavyweight Champion, two-time UFC Light heavyweight Champion, an interim UFC Light heavyweight Champion, making him a six-time UFC Champion and the UFC 13 Heavyweight Tournament winner. He is the first of seven fighters to hold two UFC championship titles in two different divisions (along with B.J. Penn, Conor McGregor, Georges St-Pierre, Daniel Cormier, Amanda Nunes and Henry Cejudo).

Couture has competed in a record 16 title fights. He is tied for the record for the most wins in UFC Heavyweight Championship bouts (6) with former UFC Heavyweight champion Stipe Miocic. He had the most title reigns in the UFC, with six. His last fight with Lyoto Machida marked his 24th fight in the UFC. He is the fourth member of the UFC Hall of Fame. He is one of only 2 over the age of 40 to have won a UFC championship fight, having done so four times. He is one of the few MMA champions to regain a title he had lost, and the only to have done it three times (twice at heavyweight, once at light heavyweight).

Couture was an Olympic wrestling alternate and has lived in Corvallis, Oregon throughout much of his career, where he served as an assistant wrestling coach and a strength and conditioning coach for Oregon State University. He established Team Quest with Matt Lindland and Dan Henderson, a training camp for fighters, based out of Gresham, Oregon, and headed by coach Robert Folis. In 2005, he moved to Las Vegas, where he opened his own extensive chain of gyms under the name Xtreme Couture. He partnered with Bas Rutten to open Legends Gym in Hollywood, California.

Couture is generally recognized as a clinch and ground-and-pound fighter who uses his wrestling ability to execute take downs, establish top position and successively strike the opponent on the bottom. He has displayed a variety of skills in boxing and catch wrestling. He is the only UFC fighter to win a championship after becoming a Hall-of-Famer and is the oldest champion in MMA history with his title victory over Tim Sylvia at age 43.