斯洛普县（Slope County, North Dakota）是位于美国北达科他州西南部的一个县，西邻蒙大拿州。面积3,158平方公里。根据美国2000年人口普查，共有人口767人。县治阿米登 （Amidon）人口只有26人，是全美人口第二少的县城。

成立于1914年11月3日，县政府成立于1915年1月14日。县名来自密苏里高原 （又称密苏里斜坡）。该州的最高点怀特峰 （White Butte，海拔1,069公尺）位于本县。

Slope County is a county located in the U.S. state of North Dakota. As of the 2010 census, the population was 727, making it the least populous county in North Dakota and the 20th-least populous county in the United States. The county seat is Amidon. The county was created in 1914 when Billings County was subdivided into three new counties; it was organized on January 14, 1915. The name refers to the Missouri Slope, a geographical feature that is also a popular designation for western North Dakota, particularly the area west of the Missouri River.