The 2012–13 Basketball League Belgium Division I, for sponsorship reasons named 2012–13 Ethias League, was the 85th season of the top tier basketball league in Belgium.

The season started on October 6, 2012 and finished on June 9, 2013.

The season ended with the defending champions Telenet Oostende defeating Belfius Mons-Hainaut in three games to win its 14th national title.