Chase County is a county located in the U.S. state of Kansas. Its county seat and most populous city is Cottonwood Falls. As of the 2020 census, the county population was 2,572. The county was named for Salmon Chase, a U.S. Senator from Ohio that was a Kansas statehood advocate.

Salmon Portland Chase was an American politician and jurist who served as the sixth chief justice of the United States from 1864 to his death in 1873. Chase served as the 23rd governor of Ohio from 1856 to 1860, represented Ohio in the United States Senate from 1849 to 1855 and again in 1861, and served as the 25th United States Secretary of the Treasury from 1861 to 1864 during the administration of Abraham Lincoln. Chase is therefore one of the few American politicians who have served in all three branches of the federal government, in addition to serving in the highest state-level office. Prior to his Supreme Court appointment, Chase was widely seen as a potential president.