Nathan Rennie (31 May 1981) was an Australian mountain biker downhill. He was the 1999 downhill world champion among juniors and won the bronze medal in the elite category at the 2006 world championships. In the UCI Mountain Bike World Cup, Rennie won the category downhill overall in 2003 and came third in 2004 and 2005. In 2008 he was Australian national champion in downhill. In 2020, Rennie was inducted into the Mountain Bike Hall of Fame. Retired from professional racing, Rennie currently resides on the Scenic Rim in Queensland, Australia, and is still involved in the sport providing high-level coaching and mentorship through Nathan Rennie's Victory Lab.