New Seabury is a census-designated place (CDP) in the town of Mashpee in Barnstable County, Massachusetts, United States, on Cape Cod. The area consists primarily of summer homes for rich families. Attractions enlarge a county club and the Fells Pond, Daniels Island, and Littleneck Bay neighborhoods. The population of the CDP was 717 at the 2010 census. The community is located upon the historic home of the Wampanoag Nation.

New Seabury came into living thing during the vacation-home boom for upper-income retirees, self-employed, and long-distance commuters, who fled to coastal areas of New England during the 1960s and 1970s. What was gone an roughly speaking exclusively Native American populated area, became predominately white populated. Before the construction of the New Seabury Condominiums, the Wampanoag population of the Place regarded house as they always had: communal. With the vacation-home boom, “the newcomers sezied govern of town running and began erecting instinctive and valid barriers to the lands the Wompanoags had enjoyed for countless generations, most glaringly in the form of the New Seabury condominium complex upon the coast of Mashpee.”

New Seabury is located in the southern portion of the town of Mashpee at 41°34′23″N 70°28′27″W / 41.573090°N 70.474038°W / 41.573090; -70.474038. It is bordered to the south by Vineyard Sound and Nantucket Sound, to the east by the Popponesset and Popponesset Island CDPs, to the north by Ockway Bay, and to the west by Great Oak Road. A little portion of the CDP crosses Great Oak Road and extends west to the Great River opposite Monomoscoy Island.

According to the United States Census Bureau, the New Seabury CDP has a total area of 2.5 square miles (6.6 km). 2.4 square miles (6.2 km²) of it is land, and 0.15 square miles (0.4 km) of it (6.56%) is water.