Seabrook sits at New Hampshire's southeastern corner in Rockingham County, where a short stretch of Atlantic beachfront meets extensive salt marshes along the Hampton and Blackwater rivers. The town's identity is split between its beach community and its role as home to the Seabrook Station nuclear power plant.

Seabrook Beach draws summer visitors to its boardwalk, arcades, and seafood restaurants, while the marshlands to the west support fishing, birdwatching, and clamming. The nuclear plant remains one of the town's largest employers and taxpayers, funding much of the local budget.

Housing ranges from modest beach cottages to year-round residential neighborhoods further inland, with prices rising in recent years alongside broader Seacoast demand. Seabrook attracts beach-goers, retirees, and workers connected to the power plant and nearby outlet shopping in Kittery, Maine.