A promoter of women in sport, in the mid-1970s, she joined Billie Jean King in establishing the Women's Sports Foundation. She served as the first President (1979–1984) and subsequently, became the chairman and Honorary Trustee for the Foundation. Under de Varona's leadership, the Women's Sport Foundation initiated the Hall of Fame Dinner (now the Annual Salute to Women in Sports Awards Dinner), Travel and Training Grants, research projects, a toll-free telephone number and annual visits to Washington, D.C., to educate Congress about Title IX and the importance of providing sport and physical activity opportunities on an equitable basis to both men and women. Over the years, the Foundation has raised more than $30 million to support its programs.