The Swan Pond River and Upper County Road demarcate Dennis Port's western border with West Dennis. The village of West Harwich lies directly to Dennis Port's east, with the border demarcated by the median of Division Street. To the north of Dennis Port is South Dennis. Like other villages along Nantucket Sound, Dennis Port features warm-water beaches, like Haigis Beach, Sea Street Beach, and Glendon Road Beach. Many consider these among Cape Cod's most desirable beaches for swimming and windsurfing.
By U.S. standards, real estate prices in Dennis Port remain high. Housing stock consists mostly of World War II–era beach cottages built in the Cape Cod architectural style, although many have been expanded or replaced with larger, more contemporary beach houses. Many streets in Dennis Port—particularly those south of Lower County Road, within of the beaches—evoke the quaint ambience of an early-20th century seasonal retreat. There are a great deal of hotels, cottage retreats, and businesses geared towards tourists.
Famous residents of Dennis Port include U.S. military hero Benjamin F. Baker.
Dennis was first settled in 1639, by John Crowe (later Crowell), Antony Thacher and Thomas Howes, as part of the town of Yarmouth. The town officially separated and incorporated in 1793. It was named after resident minister, Rev. Josiah Dennis. There was not enough land for farming, so seafaring became the town's major industry in its early history, centered around the Shiverick Shipyard.
Currently, Dennis is a popular seaside resort town, notable for its stately colonial mansions along the northern Cape Cod Bay coastline, and its picturesque, warm-water beaches along the southern Nantucket Sound.
The Cape Playhouse, in northern Dennis, is one of the oldest summer theatres in the United States (it is not clear which theatre is the oldest, as many make this claim), and among the best known. The actress Bette Davis was "discovered" while working there as an usher. Other famous Dennis residents include the author Mary Higgins Clark and actress Amy Jo Johnson, who grew up in Dennis.