Mary Claire Cheney (; born March 14, 1969) is the younger of the two daughters of Dick Cheney, the 46th vice president of the United States and 17th United States secretary of defense, and Lynne Cheney. She is involved with a number of political action committees. She married her wife, Heather Poe, in 2012, and was a signatory to an amicus curiae brief submitted to the U.S. Supreme Court in support of same-sex marriage during the Hollingsworth v. Perry case in 2013.
