At the time of first European encounter, the inhabitants of what would become Fairfax County were an Algonquian-speaking sub-group called the Taux, also known as the Doeg or Dogue.
Their villages, as recorded by Captain John Smith in 1608, included Namassingakent and Nemaroughquand on the south bank of the Potomac River in what is now Fairfax County.
Virginian colonists from the Northern Neck region drove the Doeg out of this area and into Maryland by 1670.

Fairfax County was formed in 1742 from the northern part of Prince William County.
It was named after Thomas Fairfax, 6th Lord Fairfax of Cameron (1693–1781), proprietor of the Northern Neck.
The Fairfax family name is derived from the Old English phrase for "blond hair" – Fæger-feax.

The oldest settlements in Fairfax County were along the Potomac River.
George Washington settled in Fairfax County and built his home, Mount Vernon, facing the river.
Gunston Hall, the home of George Mason is nearby.
Modern Fort Belvoir is partly on the estate of Belvoir Manor, built along the Potomac by William Fairfax in 1741.

Thomas Fairfax, 6th Lord Fairfax of Cameron, the only member of the British nobility ever to reside in the colonies, lived at Belvoir before he moved to the Shenandoah Valley.
The Belvoir mansion and several of its outbuildings were destroyed by fire immediately after the Revolutionary War in 1783, and George Washington noted the plantation complex deteriorated into ruins.

In 1757, the northwestern two-thirds of Fairfax County became Loudoun County.
In 1789, part of Fairfax County was ceded to the federal government to form Alexandria County of the District of Columbia.
Alexandria County was returned to Virginia in 1846, reduced in size by the secession of the independent city of Alexandria in 1870, and renamed Arlington County in 1920.
The Fairfax County town of Falls Church became an independent city in 1948.
The Fairfax County town of Fairfax became an independent city in 1961.

Located near Washington, D.C., Fairfax County was an important region in the Civil War.
 The Battle of Chantilly or Ox Hill, during the same campaign as the second Battle of Bull Run, was fought within the county; Bull Run is the border between Fairfax and Prince William Counties.
Other areas of activity included Minor's Hill, Munson's Hill, and Upton's Hill, on the county's eastern border, overlooking Washington, D.C.
The federal government's growth during and after World War II spurred rapid growth in the county and made the county increasingly suburban.
Other large businesses continued to settle in Fairfax County and the opening of Tysons Corner Center spurred the rise of Tysons Corner.
The technology boom and a steady government-driven economy also created rapid growth and an increasingly growing and diverse population.
The economy has also made Fairfax County one of the nation's wealthiest counties.

A general aviation airport located along U.S. Route 50, west of Seven Corners called the Falls Church Airpark operated in the county from 1948 to 1960.
The facility's 2,650 foot unpaved runway was used extensively by private pilots and civil defense officials.
Residential development, multiple accidents, and the demand for retail space led to its closure in 1960.
At the time of first European encounter, the inhabitants of what would become Fairfax County were an Algonquian-speaking sub-group called the Taux, also known as the Doeg or Dogue. Their villages, as recorded by Captain John Smith in 1608, included Namassingakent and Nemaroughquand on the south bank of the Potomac River in what is now Fairfax County. Virginian colonists from the Northern Neck region drove the Doeg out of this area and into Maryland by 1670.
Fairfax County was formed in 1742 from the northern part of Prince William County. It was named after Thomas Fairfax, 6th Lord Fairfax of Cameron (1693–1781), proprietor of the Northern Neck. The Fairfax family name is derived from the Old English phrase for "blond hair" – Fæger-feax.
The oldest settlements in Fairfax County were along the Potomac River. George Washington settled in Fairfax County and built his home, Mount Vernon, facing the river. Gunston Hall, the home of George Mason is nearby. Modern Fort Belvoir is partly on the estate of Belvoir Manor, built along the Potomac by William Fairfax in 1741.
Thomas Fairfax, 6th Lord Fairfax of Cameron, the only member of the British nobility ever to reside in the colonies, lived at Belvoir before he moved to the Shenandoah Valley. The Belvoir mansion and several of its outbuildings were destroyed by fire immediately after the Revolutionary War in 1783, and George Washington noted the plantation complex deteriorated into ruins.
In 1757, the northwestern two-thirds of Fairfax County became Loudoun County. In 1789, part of Fairfax County was ceded to the federal government to form Alexandria County of the District of Columbia. Alexandria County was returned to Virginia in 1846, reduced in size by the secession of the independent city of Alexandria in 1870, and renamed Arlington County in 1920. The Fairfax County town of Falls Church became an independent city in 1948. The Fairfax County town of Fairfax became an independent city in 1961.
Located near Washington, D.C., Fairfax County was an important region in the Civil War.  The Battle of Chantilly or Ox Hill, during the same campaign as the second Battle of Bull Run, was fought within the county; Bull Run is the border between Fairfax and Prince William Counties. Other areas of activity included Minor's Hill, Munson's Hill, and Upton's Hill, on the county's eastern border, overlooking Washington, D.C.
The federal government's growth during and after World War II spurred rapid growth in the county and made the county increasingly suburban. Other large businesses continued to settle in Fairfax County and the opening of Tysons Corner Center spurred the rise of Tysons Corner. The technology boom and a steady government-driven economy also created rapid growth and an increasingly growing and diverse population. The economy has also made Fairfax County one of the nation's wealthiest counties.
A general aviation airport located along U.S. Route 50, west of Seven Corners called the Falls Church Airpark operated in the county from 1948 to 1960. The facility's 2,650 foot unpaved runway was used extensively by private pilots and civil defense officials. Residential development, multiple accidents, and the demand for retail space led to its closure in 1960.
Fairfax County, Virginia