Grant Karlus Mizens, OAM (born 19 April 1977) is an Australian wheelchair basketball player. He won one gold and two silver medals at the Summer Paralympics. In June 2025, he was appointed the President of Paralympics Australia. As Paralympics Australia President, he became Vice President on the Brisbane Organising Committee for the 2032 Olympic and Paralympic Games.
He is classified as a 2.0 player and plays guard.
He was part of the Australia men's national wheelchair basketball team that won a silver medal at the 2004 Summer Paralympics, and also part of the team that won a gold medal at the 2008 Summer Paralympics, for which he received a Medal of the Order of Australia. At the 2012 Summer Paralympics he was part of the Australian men's wheelchair team that won silver.
He was a member of the national team that competed at the 2009 IWBF Asia Oceania Championships. He was a member of the Australia men's national wheelchair basketball team that competed at the 2010 Wheelchair Basketball World Championship that won a gold medal.
Mizens played club basketball for the West Sydney Razorbacks. In 2010, he was playing club basketball with the Wenty League Wheelkings.
He was born in Sydney, New South Wales. Mizens in his final year of high school was involved in a car accident that led to paraplegia from the waist down. Mizen has completed a Bachelor of Arts in Economics from the University of Illinois and is a Graduate member of the Australian Institute of Company Directors.
In 2020, he was appointed to Paralympics Australia Board, in March 2023 elected vice president and in June 2025 was appointed President. In 2024, he is Portfolio Manager at MLC Asset Management and a member of Sargood Foundation and Sargood Centre Boards.