Harlan is a lunar impact crater near the southeastern limb of the Moon.
To the northeast is the flooded walled plain Abel, and to the southeast is Mare Australe.
The inner wall has slumped to form a shelf along the northwestern side.
The interior floor has been resurfaced by basaltic lava, producing a level, nearly featureless surface with a lower albedo than its surroundings.
Harlan was previously designated Marinus D before being assigned its current name by the IAU.