昂托纳贡县（Ontonagon County, Michigan）是美国密西根州上半岛西部的一个县，北临苏必利尔湖。面积9,690平方公里（水面面积为6,293平方公里，即占总面积64.95%）。根据美国2000年人口普查，共有人口7,818人。县治昂托纳贡（Ontonagon）。

成立于1843年3月9日，县政府成立于1853年1月1日。县名来自昂托纳贡河，原来是一个意义不明的印第安词语，可能是「碗」、「渔场」或「狩猎河」的意思。。

Ontonagon County (/ˌɒntəˈnɑːɡən/ ON-tə-NAH-gən) is a county located in the Upper peninsula of the U.S. state of Michigan. As of the 2010 census, the population was 6,780, making it the third-least populous county in Michigan. The county seat is Ontonagon. The county was set off in 1843, and organized in 1848. Its territory had originally been organized as part of Chippewa and Mackinac counties. With increasing population in the area, more counties were organized. After Ontonagon was organized, it was split to create Gogebic County.