The South Shore of Massachusetts is a geographic region stretching south and east from Boston toward Cape Cod along the shores of Massachusetts Bay and Cape Cod Bay. It is subject to varying descriptions including municipalities in eastern Norfolk and Plymouth counties.

Depending on its geographical definition, the South Shore is composed of a mix of suburban towns, mid-sized industrial cities and rural towns. Massachusetts' heaviest concentration of Irish-American residents and descendants from ancestors from Ireland is on the South Shore,^[1] and 6 of the United States' 10 most Irish towns are located on the South Shore, which is sometimes referred to locally as the "Irish Riviera".^[2][3]

By its most literal definition, the South Shore includes only cities and towns between Boston and Cape Cod that physically border the Atlantic Ocean, thereby limiting the South Shore to the following:

The Massachusetts Office of Coastal Zone Management limits its definition of the South Shore to the municipalities between Boston Harbor and Cape Cod, which includes Atlantic coastal and coastal watershed areas "from the three-mile (5 km) limit of the state territorial sea to 100 feet (30 m) beyond the first major land transportation route encountered (a road, highway, rail line, etc.)".^[4] This definition eliminates Braintree, Quincy and Weymouth, which border Boston Harbor, but adds the towns of Hanover, Norwell and Pembroke.^[5]

In the official sense of the South Shore, however, some of these coastal communities are either members of the Boston-centered Inner Core Committee of the Metropolitan Area Planning Council (MAPC)^[6] or not part of the metropolitan area at all, while the South Shore Coalition of the MAPC comprises representatives from 14 coastal and inland communities^[7] and includes the following cities and towns:

Institutions of higher learning which serve South Shore communities include: