Seaside Park, located in Bridgeport, Connecticut, is a 2.5-mile (4.0 km) long crescent-shaped park bordering Bridgeport Harbor, Long Island Sound, and Black Rock Harbor. The park lies within Bridgeport's South End neighborhood.

Bridgeport is the most populous city in the U.S. state of Connecticut and the fifth-most populous city in New England, with a population of 148,654 in 2020. Located in eastern Fairfield County at the mouth of the Pequonnock River on Long Island Sound, it is a port city 60 miles (97 km) from Manhattan and 40 miles (64 km) from The Bronx. It borders the towns of Trumbull to the north, Fairfield to the west, and Stratford to the east. Bridgeport and other towns in Fairfield County make up the Greater Bridgeport Planning Region, as well as the Bridgeport–Stamford–Norwalk–Danbury metropolitan statistical area, the second largest metropolitan area in Connecticut. The Bridgeport–Stamford–Norwalk–Danbury metropolis forms part of the New York metropolitan area.