Luz Mercedes Acosta Tollefson (born December 22, 1980, in Guaymas, Sonora, Mexico) is a Mexican former weightlifter who competed for her native country at the Olympic level.

Later on she participated at the 2011 Pan American Games at Guadalajara, Mexico, where she won the bronze medal.

She participated in the 63 kg category, finishing in 6th place.

[2][3] Years later, positive doping tests for the gold and silver medalists raised the prospect of her being upgraded to the bronze medal position in the 2012 Olympic event.

Acosta expressed disappointment at not having been able to stand on the podium at the Olympics itself, but was pleased at having set an example for clean competition.