The Vicky Cristina Barcelona star will be photographed wearing the 2012 Key To The Cure T-shirt, which will be sold in Saks Fifth Avenue stores this autumn (12) to raise money for the Women's Cancer Research Fund.
The fund benefits charities aiming to find innovative detection methods, better treatments and eventual cures for cancer.
Cruz says, "I am honoured to join the Entertainment Industry Foundation's Women's Cancer Research Fund and Saks Fifth Avenue to raise awareness for women's cancers. Cancer has affected each and every one of us in one way or another and I am thrilled to be involved with this wonderful cause."
Previous ambassadors for the annual initiative include Hollywood beauties Gwyneth Paltrow and Uma Thurman.