The South Coast of Massachusetts is the region of southeastern Massachusetts consisting of the southern Bristol and Plymouth counties, bordering Buzzards Bay, and includes the cities of Fall River, New Bedford, the southeastern tip of East Taunton and nearby towns. The Rhode Island towns of Tiverton and Little Compton, located in Newport County, are often included within the South Coast designation due to regional similarities with adjacent communities.

Southeastern Massachusetts is a region of Massachusetts located south of Boston and east of Rhode Island. It is commonly used to describe areas with cultural ties to both Boston and Providence, Rhode Island, and includes the cities of New Bedford and Fall River and their respective suburbs. Despite the location of Cape Cod and the islands to its south, which are the southeasternmost parts of the state, they are not often grouped in this designation. At its broadest definition, it includes all of Massachusetts south of Boston, southeast of Worcester, and east of Providence, Rhode Island, while at its narrowest definition, it is Bristol County and the Western portion of Plymouth County.