Luka Mladenovic (born 27 May 2004) is an Austrian competitive swimmer. At the 2022 World Junior Championships, he won the gold medal and world junior title in the 100-metre breaststroke, the silver medal in the 200-metre breaststroke, and the bronze medal in the 50-metre breaststroke. He is a 2022 European Junior Championships silver medalist in the 200-metre breaststroke.