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 (40 km) radius and more than 1.4 million in a 50-mile (80 km) radius.

Palm Beach County is a county in the southeastern part of Florida, located in the Miami metropolitan area. It is Florida's third-most populous county after Miami-Dade County and Broward County and the 26th-most populous in the United States, with 1,492,191 residents as of the 2020 census. Its county seat and largest city is West Palm Beach, which had a population of 117,415 as of 2020. Named after one of its oldest settlements, Palm Beach, the county was established in 1909, after being split from Miami-Dade County. The county's modern-day boundaries were established in 1963.