Blenheim is a town in Marlboro County, South Carolina, United States. The population was 137 at the 2000 census. It is named for Blenheim Palace in Oxfordshire, England which itself is named for the Battle of Blenheim, a major English victory of the War of the Spanish Succession at what is now Blindheim, Germany. Blenheim Palace was the residence of the Duke of Marlborough, who Marlboro County is named for. Blenheim Ginger Ale was originally bottled in Blenheim, South Carolina, with the local mineral water.