Sully Historic Site, is both a Virginia landmark and nationally registered historic place in Chantilly, Virginia.

The earliest recorded claim to the land was made by the Doeg. Later the Lee family of Virginia owned the land from 1725 to 1839. Richard Bland Lee did not build the main house until 1794. Following the purchase by William Swartwort in 1838, Sully was used as a home, a working farm, or both by a series of private owners. Then in 1958, Sully was acquired by the federal government as a part of the area to be used for the construction of Dulles Airport. Today the Fairfax County Park Authority operates the site with a specific focus on the Lee family.

The land that would become part of Sully was likely controlled by several groups before the Doeg claimed the area. English settlers encountered Algonquian language speaking members of the Doeg in modern-day Northern Virginia. The Doeg are most well known for their raid in July 1675 that became a part of Bacon's Rebellion. English colonists settling in modern Northern Virginia came into conflict with the Doeg from 1661 to 1664. When diplomatic attempts failed, the governor sent the Rappahannock County militia in June 1666. The specifics of that military action are unclear, but later land grants to English settlers are not disputed, suggesting the English gained control of the area. The English presumptively took control after a violent conflict with the Doeg in 1666. Little is recorded about the disposition of this land from the time when the English gained control of it until the land is patented by the Lee family of Virginia.

Originally acquired in 1725 by Richard Bland Lee's grandfather, Henry Lee I, Sully was inherited by Richard's father Henry Lee II of "Leesylvania". At his death in 1787, the land was divided between Richard and his younger brother Theodorick Lee. Being the older of the two, Richard was given the more alluvial northern half, having resided there as manager of the property since approximately 1781. During this period the predominant crop grown was tobacco.

Richard severely curtailed tobacco production in favor of more sustainable crops, including wheat, corn, rye, and barley. This reduced the soil depletion inherent to tobacco production, and allowed for the practice of crop rotation. He also planted fruit orchards, including peach and apple trees, which he used to produce spirits. In 1801 Richard constructed a dairy, which ran primarily under the supervision of his wife Elizabeth Collins Lee.

After his election to the United States Congress in 1789, and for most of the next five years, Richard turned day-to-day management of his estate over to his brother Theodorick, who supervised spring planting and fall harvest. Theodorick also managed the collection of rent from tenant farmers and the construction of the large house Richard had planned for the estate, on which construction had begun in 1794. Before he left for Congress in 1789, Richard had chosen the name "Sully" for his estate.

By 1811, having been drawn into heavy debt trying to aid his brothers, Henry Lee III and Charles Lee, extricate themselves from severe financial difficulties, Richard Bland Lee decided he could no longer sustain ownership of Sully. Accordingly, he decided to sell the plantation to raise cash to pay some of the debt. He sold Sully for $18,000 to his second cousin, Francis Lightfoot Lee II, son of Richard Henry Lee.

For several years after his purchase of Sully, Francis Lightfoot Lee II, called F. L. by his family, was able to realize an annual profit of $1,500 to $2,500. At least part of that success was due to the "judicious system of husbandry" employed by F. L.'s wife Jane Fitzgerald Lee. Then in 1816, due to complications during the delivery of their fifth child Frances Ann Lee, Jane Fitzgerald Lee died. Four years later in 1820, F. L. had either a nervous breakdown or stroke. Unable to care for himself, he was committed to the Pennsylvania Hospital in Philadelphia in 1825.