The New England traditional-style two-story, with four bedrooms and 4 1/2 bathrooms in 3,841 square feet, has a fireplace in the living room, a formal dining room and a kitchen that opens to the family room.
The gated house sits behind hedges on less than acre with a swimming pool, a brick patio, flat lawn and a matching treehouse.
Dempsey, 43, earned the nickname Dr. McDreamy for his portrayal of Dr. Derek Shepherd on the ABC medical drama (2005-present). He also starred in the movies "Made of Honor" (2008) and "Enchanted" (2007).
The actor listed the property in March at $3,595,000. Public records show he purchased it for $3.1 million in 2006.
Brett Lawyer of Sotheby's International Realty, Sunset Boulevard office, handled both sides of the deal.