Harwich Port is a small affluent seaside community and census-designated place situated along the Nantucket Sound in the town of Harwich in Barnstable County, Massachusetts, United States. It is named after the port of Harwich in Essex, England. As of the 2010 census, the CDP had a population of 1,644. It is a popular vacation spot on Cap…Harwich Port is a small affluent seaside community and census-designated place situated along the Nantucket Sound in the town of Harwich in Barnstable County, Massachusetts, United States. It is named after the port of Harwich in Essex, England. As of the 2010 census, the CDP had a population of 1,644. It is a popular vacation spot on Cape Cod and is home to the Wychmere Beach Club and the Allen Harbor Yacht Club. Also, one of its popular mottos is "Three Harbors, One Port," referencing to Saquatucket, Wychmere, and Allen Harbor, which are all located in Harwich Port. Well known residents include Bill O'Brien, former head coach and general manager of the Houston Texans, an American football team.