Horry County (pronounced O'Ree) was created from Georgetown District in 1801. At that time, the county had an estimated population of 550. Isolated by the many rivers and swamps typical of the South Carolina Low Country, the area was essentially surrounded by water, forcing its inhabitants to survive virtually without assistance from the "outside world". This caused the county residents to become an extremely independent populace, and they named their county "The Independent Republic of Horry". The county was named after, and in honor of, Revolutionary War hero Peter Horry who was born in South Carolina around 1743. Horry started his military career in 1775 as one of 20 captains, elected by the Provincial Congress of South Carolina, to serve the 1st and 2nd Regiments. In 1790, he was assigned to the South Carolina militia under Brigadier General Francis Marion

The population has increased more than fourfold since 1970, as the area has become a destination for retirees and people owning second homes. It has been developed for resorts and retirement communities. The majority-white residents have constituted a majority-Republican voter base since the late 20th century.