The 2009–10 ACB season was the 27th season of the Liga ACB.

The regular season began on Saturday, October 10, 2009, and ended on Sunday, May 16, 2010.

Italics indicate holder of a Euroleague "A License", giving the team automatic access to the 2010–11 Euroleague Regular Season regardless of league placement.

Final standings: Last updated: May 19, 2010.Source: ACB

Last updated: May 16, 2010.Source: ACB