Follet's Island is a barrier island on the Texas Gulf Coast in Brazoria County, Texas, immediately southwest of Galveston Island. It forms part of the Texas barrier islands chain that protects the mainland from storm surges and coastal erosion.
The island separates Christmas Bay and Drum Bay from the Gulf of Mexico, creating a unique estuarine environment. It is approximately 13 miles (21 km) long and averages 3.5 feet (1.1 m) above mean sea level, making it highly vulnerable to storm surge and coastal flooding.