Chickasha ) is a city in and the county seat, business and employment center of Grady County, Oklahoma, United States. The population was 15,850 at the 2000 census. Chickasha is home to the University of Science and Arts of Oklahoma and hosts an annual Festival of Light celebration located at Shannon Springs Park. The city is named for, and strongly connected to Native American heritage as Chickasha (Chikashsha) is the Choctaw word for Chickasaw.