Margaret Gallagher (born September 14, 1960) is an American writer, socially conservative commentator, and activist. She wrote a syndicated column for Universal Press Syndicate from 1995 to 2013 and has written several books. Gallagher founded the Institute for Marriage and Public Policy, a small, socially conservative think tank. She is also a co-founder of the National Organization for Marriage (NOM), an advocacy group which opposes same-sex marriage and other legal recognition of same-sex partnerships; she has served as president and as chairman of the board of NOM.