South Bay is a city in Palm Beach County, Florida, United States. It is the westernmost municipality in the South Florida metropolitan area. As of 2020, the population recorded by the U.S. Census Bureau was 4,860 residents. While the current estimates place South Bay's population in the incorporated city limits at more than 4,000 people, surrounding areas increase the population figures to 54,000 people in a 25-mile radius and more than 1.4 million in a 50-mile radius.