Okolona is a city in and one of the two county seats of Chickasaw County, Mississippi, United States. It is located near the eastern border of the county. The population was 2,692 at the 2010 census.
Okolona was named as Rose Hill in 1845 early in its settlement, but residents later discovered that another location had this name. When a US post office was established here in 1850, a new name was needed to avoid confusion in mail delivery. According to the Okolona Area Chamber of Commerce, Colonel Josiah N. Walton, postmaster of nearby Aberdeen, remembered an encounter with a Chickasaw warrior years earlier. The man's name was Oka-laua, meaning peaceful, yellow, or blue water. Walton renamed Rose Hill as Okolona in his honor.
Due to the destruction brought to the area by the Civil War, few structures from the antebellum period remain. The Elliott-Donaldson House, constructed in 1850, survives and was added to the National Register of Historic Places in 1980. A few other homes have also survived.