With their every move followed by paparazzi, plus a built-in fan base, the possibility for high-profile moms to influence charitable giving is almost unmatched. We chose our Most Powerful Moms: Celebrity Moms Who Give with specific criteria in mind. First, the women on this list have not only opened up their checkbooks, they have personally dived into the charities that matter to them—visiting war-torn nations as United Nations Goodwill Ambassadors to dispense supplies, spearheading social media campaigns to raise awareness for causes and acting as lobbyists in Washington. Each woman has at least one child in her household under 18 years old. And they’re all determined to leverage their fame and privilege to make a true difference.

See the complete list of the Most Powerful Moms: 15 Celebrites Who Give

Several of the celeb moms we chose have been called to action after losing a loved one to a battle with a disease. Former Entertainment Tonight host Leeza Gibbons founded Leeza’s Place after watching her mother suffer from Alzheimer’s. With locations in California, Florida and Illinois, Leeza’s Place is a support center for families of those dealing with the illness. The Good Wife star Julianna Margulies saw her friend the theater producer Jenifer Estess die from ALS (amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease) and co-founded Project A.L.S. with Estess’s sisters. The organization has raised over $42 million since its inception in 1998.

Other women on this list are committed to helping women around the globe. Oscar-winning actress Natalie Portman is an active supporter of FINCA International (the Foundation for International Community Assistance), which provides microloans to women in developing countries. Mariska Hargitay of Law & Order: Special Victims Unit fame founded the Joyful Heart Foundation to help the survivors of domestic violence. And Geena Davis launched The Geena Davis Institute on Gender in Media in 2007, aiming to increase the number and variety of female characters aimed at children and to reduce the stereotyping of women in the media.

Academy Award winner Julia Roberts gives more than money and star power to the causes she supports. She is known to roll up her sleeves, as she did in Haiti as UNICEF’s Goodwill Ambassador in the 1990s, and as a volunteer counselor for kids at The Hole in the Wall Gang Camp, a summer camp for kids with life-threatening illnesses, something she has participated in for over 15 years. At a fund-raising event for the camp in 2009, she told the story of working with a little boy and being nearby when he made a call to his mother to tell her he had "the best counselor in the world—Tinkerbell!" (Roberts’s role in the movie Hook).

Another big-screen star, Angelina Jolie, has become the gold standard for what it looks like to be a celebrity philanthropist. Jolie has given away millions through the Maddox Jolie-Pitt Foundation to causes ranging from funding a Namibian wildlife sanctuary to starting a primary school for girls in Afghanistan. She is also an active lobbyist in Washington for the causes that matter to her—she recently met with President Barack Obama to discuss concerns she has about Bosnia and Herzegovina, the subject of her directorial debut, In the Land of Blood and Honey. And she is not afraid to get her hands dirty; during missions with the United Nations as a Goodwill Ambassador to countries like Afghanistan and Libya, she is known for staying in the same accommodations as the rest of the UN peacekeepers.

Jolie told the crowd at the Palm Springs Film Festival in 2012 about how her focus on philanthropy has impacted her parenting: “I’m not one of those moms who kind of lectures my kids. But I do tell them, whenever I go on a trip, where I’m going and why. On some occasions, they’ve come with me to different refugee camps,” she said, speaking of her six children. “Hopefully they live in the world, and they see the world really as it is, outside of Hollywood.”