sentences:  The population was 3,672 at the 2010 census.Grand Bay is located at (30.474055, -88.341836), along U.S. Route 90 midway between the Alabama/Mississippi state line and the town of St. Elmo, a few miles inland from the Mississippi Sound.According to the United States Census Bureau, the CDP has a total area of , of which is land and (0.34%) is water.