The 2016 IIHF World U18 Championship Division III Group A and 2016 IIHF World U18 Championship Division III Group B were a pair of international under-18 men's ice hockey tournaments run by the International Ice Hockey Federation. The Group A and Group B tournaments made up the sixth and seventh level of competition at the 2016 IIHF World U18 Championships. The Group A tournament took place between 14 March and 20 March 2016 in Sofia, Bulgaria. The tournament was won by Australia who gained promotion back to Division II Group B for 2017 while Mexico finished last and was relegated to Division III Group B for 2017. The Group B tournament took place from 14 February to 19 February 2016 in Cape Town, South Africa. New Zealand won the tournament and gained promotion to Division III Group A for 2017.