[4] According to the United States Census Bureau, the town has a total area of 0.3 square miles (0.78 km2), all land.

It borders the Atlantic Ocean to the northeast, Rehoboth Beach to the southeast, and unincorporated portions of Sussex County on the west and north.

[5] Henlopen Acres is divided into 216 parcels of land, on which are 205 homes, the town hall and maintenance area, the town's marina, the Henlopen Acres Beach Club, Block W Beach, and the Rehoboth Art League.

[6] Henlopen Acres has no police department, but town-owned private security began in 1996.

The security service, which patrols all of Henlopen Acres and North Shores,[6] operates two vehicles.

[6] Henlopen Acres' municipal government generally maintains amicable relations with the government of Rehoboth Beach, follows Sussex County's lead on how to react to emergencies such as major storms and whether or not to evacuate in the face of them.

Henlopen Acres and Greenville (where the DuPont estate is located) are the two richest places in Delaware, all but tied for highest personal incomes, averaging over $80,000 per annum.

Evidence of Native American activity prior to the arrival of Europeans has been found in Henlopen Acres.

[9] After the arrival of the first European settlers, organized by the Dutch merchant Samuel Blommaert (1583–1651 or 1654), the area became farmland.

However, no state highways serve the town, with only minor roads linking Henlopen Acres to surrounding areas.