Mario Leitner (born 2 February 1997) is an Austrian slalom canoeist who has competed at the international level since 2012. He won a bronze medal in extreme K1 at the 2021 World Championships in Bratislava. He also won a silver medal in the same event at the 2022 European Championships in Liptovský Mikuláš. Leitner finished 13th in the K1 event at the 2016 Summer Olympics in Rio de Janeiro.