James Magnussen (born 11 April 1991) is a retired Australian swimmer and Olympic medallist.
He was the 2011 and 2013 100-metre freestyle world champion, and holds the fifth fastest swim in history in the 100-metre freestyle, with a time of 47.10, which until 2016 also stood as the fastest swim in textile swimwear material.He has won a total of 15 medals in major international competition, seven gold, five silver and three bronze, spanning the Olympics, World Championships, Commonwealth Games, and the Pan Pacific Championships.