The 2010 IIHF World U18 Championship Division I was an international under-18 ice hockey competition organised by the International Ice Hockey Federation.

Both Division I tournaments made up the second level of the 2010 IIHF World U18 Championships.

Norway and Germany won the Group A and B tournaments respectively and gained promotion to the Top Division of the 2011 IIHF World U18 Championships.

The Group A tournament was played in Herning, Denmark, from 12 to 18 April 2010.

The Group B tournament was played in Krynica-Zdrój, Poland, from 11 to 17 April 2010.