麦肯齐县（McKenzie County）是位于美国北达科他州西部的一个县，西邻蒙大拿州。面积7,410平方公里，根据美国2000年人口普查数字，共有人口5,737人。县治瓦特福市。

McKenzie County is a county located in the U.S. state of North Dakota. As of the 2010 census, the population was 6,360. Its county seat is Watford City.

McKenzie County was first created by the March 8, 1883 Dakota Territory legislature but eliminated in 1891 due to a lack of settlement. The county was then recreated by the 1905 state legislature, with the county government first organizing on April 20, 1905. The name comes from early North Dakota politician Alexander McKenzie. Before becoming Watford City, the county seat was Alexander from 1905 to 1907 and Schafer from 1907 to 1941.