Marmarth (pronunciation: /mɑrməθ/ mar-məth) is a city in Slope County, North Dakota in the United States. The population was 136 at the 2010 census. Marmarth was founded in 1907.
Marmarth is located at 46°17′41″N 103°55′23″W / 46.29472°N 103.92306°W / 46.29472; -103.92306 (46.294693, -103.923037).
According to the United States Census Bureau, the city has a total area of 2.5 square miles (6.6 km²), all of it land.