Mark Lee McMorris (born 9 December 1993) is a Canadian professional snowboarder who specializes in the slopestyle and big air events. He was the first person ever to complete a backside triple cork 1440 and won back-to-back gold medals in the 2012 and 2013 Winter X Games in the slopestyle event. He competed in the slopestyle event at the 2014 Winter Olympics in Sochi, where he won a bronze medal, Canada's first medal in those Games. He competed at the 2018 Winter Olympics in PyeongChang, where he won a bronze medal, only 11 months after a snowboarding accident with near-fatal internal injuries.
McMorris competed at his first FIS Snowboard World Cup during the 2009–2010 season placing eighth in the big air event in Quebec City. He followed up with a World Cup victory in slopestyle in Calgary.
At the Winter X Games XV in Aspen, Colorado, he won a silver medal in the slopestyle competition finishing behind fellow Canadian Sebastien Toutant. He also won the 2011 World Snowboard Tour's Air & Style competition beating out Peetu Piiroinen, Werner Stock, and Nils Arvidsson in the final. McMorris is the first person in X Games history to score a 98.00 in snowboard slopestyle. McMorris achieved the score while defending his title in his final run at the 2013 Winter X Games. The medal had completed a double podium performance at the games where McMorris had also won the silver with his performance in the big air competition. This all occurred just several days after he won his first ever medal when he placed second at the 2013 FIS World Championships.