WEC 40: Torres vs. Mizugaki was a mixed martial arts event held by World Extreme Cagefighting on April 5, 2009 at the UIC Pavilion in Chicago, Illinois.

This was the first WEC event to exclusively feature fights in the lightweight, featherweight, and bantamweight weight classes.

World Extreme Cagefighting would maintain this weight class structure for the remainder of the promotion's existence.

WEC Bantamweight Champion Miguel Torres was to defend his title against Brian Bowles at this event, but Bowles was forced to withdraw from the bout due to a back injury, and was replaced by WEC newcomer Takeya Mizugaki.

Cole Province was originally slated to face Rafael Dias at this event, but bowed out due to an injury and was replaced by Mike Budnik.