The 2003 IIHF World U18 Championship Division III was a pair of international under-18 ice hockey tournaments run by the International Ice Hockey Federation. The Division III tournaments made up the fourth level of competition at the 2003 IIHF World U18 Championships. The Group A tournament took place between 5 and 8 March 2003 in Mexico City, Mexico and the Group B tournament took place between 6 and 9 February 2003 in Sarajevo, Bosnia and Herzegovina. The Group A competition was won by Australia while Iceland won the Group B tournament. Upon winning their respective tournaments both teams gained promotion to Division II of the 2004 IIHF World U18 Championships.