Mary Esther is a city in Okaloosa County, Florida, United States. The population was 4,055 at the 2000 census. As of 2004, the population recorded by the U.S. Census Bureau is 4,115. Mary Esther apartments for rent comparison page shows most up to date rent information on Mary Esther apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.