The 2005 IIHF World U18 Championship Division I were a pair of international under-18 ice hockey tournaments run by the International Ice Hockey Federation. The Division I tournaments made up the second level of competition at the 2005 IIHF World U18 Championships. The Group A tournament took place between 3 April and 9 April 2005 in Maribor, Slovenia and the Group B tournament took place between 2 April and 8 April 2005 in Sosnowiec, Poland. Belarus and Norway won the Group A and Group B tournaments respectively and gained promotion to the Championship Division for the 2006 IIHF World U18 Championships. While Great Britain finished last in Group A and Italy last in Group B and were both relegated to Division II for 2006.