Fort Frederik, also known as Frederiksfort, is a U.S. National Historic Landmark in Frederiksted, United States Virgin Islands.

It was built between 1752 and 1760 by Denmark-Norway to defend the economic interests of the natural deep water port of Frederiksted and to ward off pirates.

It should not be confused with Frederiks Fort, Fortberg Hill, on St. John, which is also listed on the National Register of Historic Places.

According to Westergaard, "It was soon found that a customs house was not sufficient, but that cannon must be provided, and placed as to command the roads where the ships lay anchored.

John Gottliff (also known as Moses Gotlieb, General Bordeaux, or Buddhoe) had led 8,000 blacks in a freedom march to Frederiksted.