They're using their fame and red-carpet status to help promote causes that matter.
Everything in this slideshow
Supermodel and mother of four, Klum assists the Elizabeth Glaser Pediatric AIDS Foundation, providing HIV prevention and treatment for women, children, and families.
Oscar winner and mother of two, Witherspoon serves as honorary chairperson of the Avon Foundation, a nonprofit that tackles breast cancer and domestic violence.
The singer and new mom is a cofounder and global ambassador for Keep a Child Alive. The organization provides treatment and support to children and families affected by HIV/AIDS in Africa and India.
Originally published in the May 2011 issue of Parents magazine.