Mary Kathryn Heitkamp is an American lobbyist, lawyer, and politician who served as a United States senator from North Dakota from 2013 to 2019. A member of the North Dakota Democratic–Nonpartisan League Party, she was the first woman elected to the U.S. Senate from North Dakota. Heitkamp served as the 28th North Dakota attorney general from 1992 to 2000 and 20th North Dakota tax commissioner from 1986 to 1992. As of 2021, she is the last Democrat to hold statewide office in North Dakota.