Clark County is a county located in the U.S. state of Nevada. As of the 2020 census, the population was 2,265,461. Most of the county population resides in the Las Vegas Census County Divisions, which hold 2,196,623 people as of the 2020 Census, across 435 square miles. It is by far the most populous county in Nevada, and the 11th most populous county in the United States.