埃尔科县（英语：Elko County），美国内华达州东北部的一个县，东邻犹他州，北、东北邻爱达荷州。面积44,555平方公里，是美国面积第四大的县份。根据2010年人口普查，埃尔科县共有人口48,818人。埃尔科县的县治为埃尔科。

埃尔科县成立于1869年3月5日，是独立自兰德县的。县名是印第安语「白人女子」或者「美丽」的意思；另一说认为是铁路大亨查尔斯·克罗克为车站命名时，在原名Elk（在周围常见的马鹿）的站名后加上「o」。

Elko County is a county located in the U.S. state of Nevada. As of the 2010 census, the population was 48,818. Its county seat is Elko. The county was established on March 5, 1869, from Lander County.

Elko County is the fourth-largest county in the contiguous United States, ranking lower when the boroughs of Alaska are included. It is also one of only 10 counties in the U.S. with more than 10,000 square miles (25,900 km) of area.