Fremont County is a county in the U.S. state of Wyoming. As of the 2010 United States Census, the population was 40,123. Its county seat is Lander. The county was founded in 1884 and is named for John C. Frémont, a general, explorer, and politician. It is roughly the size of the state of Vermont.
Fremont County comprises the Riverton, WY Micropolitan Statistical Area.
Fremont County was created on March 5, 1884 by the legislature of the Wyoming Territory. The county was created with land ceded by Sweetwater County. In 1890, Big Horn County was carved out of Fremont, Johnson, and Sheridan Counties. Hot Springs County was created in 1911 from parts of Fremont, Big Horn, and Park counties. In 1921, Sublette County was created from parts of Fremont and Lincoln counties, leaving Fremont County's boundary at its present configuration.
Fremont County was named for John Charles Frémont, an explorer of the American West, United States Senator from California, and 1856 Republican presidential candidate. Fremont County is the site of the Wind River Indian Reservation, home of the Eastern Shoshone and Northern Arapaho tribes of Native Americans.