Mary Frances Tarlton "Sissy" Farenthold (October 2, 1926 – September 26, 2021) was an American politician, attorney, activist, and educator.

She ran against Jack K. Pedigo of Corpus Christi, Texas, graduate of the University of Michigan Law School and World War II veteran.

Farenthold founded the Public Leadership Education Network in 1978 with key support for her vision from Ruth Mandel, who directed the Center for American Women and Politics, which is a part of the Eagleton Institute of Politics at Rutgers University and Betsey Wright, who headed the National Women's Education Fund.

She also continued to devote significant time to the international women’s movement and began a collaboration with her cousin, Genevieve Vaughan, that would last the next decade.

[7] Farenthold and Vaughan organized the Peace Tent at the 1985 U.N. NGO Forum in Nairobi, Kenya, in conjunction with the third United Nations World Conference on Women.

[6] Farenthold worked with the Institute for Policy Studies (IPS), a progressive multi-issue think tank devoted to peace, justice, and the environment.

She was an emeritus trustee for the Institute for Policy Studies and served on the advisory board of the Bernard and Audre Rapoport Center for Human Rights and Justice at the University of Texas.

[9] Her step-grandson, Blake Farenthold, was elected in 2010 to the U.S. House of Representatives from Texas as a Republican, and served as a member of the Tea Party Caucus until he resigned April 6, 2018, due to allegations he used $84,000 of taxpayer money to pay a settlement to a former aide who accused him of sexual harassment and other improper conduct.