Warren Adelson, an art historian and top gallery owner who specializes in American Impressionist art, and his wife, Jan, have just sold their own real estate treasure — Rabbit Hill, otherwise known as Sleepy Hollow’s own Downton Abbey, for $9 million.

Adelson is the the owner of Adelson Galleries at 730 Fifth Ave. Rabbit Hill features a stately Georgian-style country house, built circa 1929, which sits on 15 acres and overlooks the Hudson River.

The purchase price includes an additional six acres, sources tell Gimme Shelter.

The mansion was designed by Mott B. Schmidt, whose clients included the Astor, Rockefeller and Vanderbilt families.

Schmidt also designed the 1960s addition to Gracie Mansion. Completely restored, the 16,000-square-foot residence features marble, brick, “random-width” wood floors, original paneling and moldings, “one-of-a-kind” fireplace mantels, a formal dining room and a walnut-paneled library.

Multiple French doors in the main rooms open to the terrace and Hudson River views.

The gated property is across from the Rockefeller family holdings and come with formal gardens.

The property also includes a brick carriage house, a large pool house and a greenhouse.

The broker, David Turner, of Houlihan Lawrence, declined to comment.