is an unincorporated village located on the John Mosby Highway (U.S. Route 50) between Gilbert's Corner and Middleburg in Loudoun County, Virginia. It is located in a gap between the Catoctin Mountain and Bull Run Mountain, through which the Little River flows. The zip code for Aldie, Virginia, is 20105.
Aldie's beginnings were laid in 1765 when James and George Mercer established a mill at the location of the present historic edifice. The location was a natural choice, as the gap contained the intersection of the Belhaven road between Winchester and Alexandria and the Mountain road which ran northwest to Snickers Gap. By 1809 the Little River Turnpike was completed from Alexandria to the Mercer Mill, replacing the older rutted section of Belhaven Road. With the opening of the road, James Mercer's son, Charles Fenton Mercer, in a partnership with William Cooke set out to develop a village on at the turnpike's western terminus. Mercer named the village for Castle Aldie, his Scottish clan's ancestral home.
By 1811 a post office had been established in the burgeoning village. Two years later, the Ashby's Gap Turnpike was completed from Aldie to Middleburg, and in 1818 the Snickersville Turnpike opened, replacing the Mountain Road, setting up Aldie for its rise to prominence. By the census of 1820, Aldie had a population of 248 residents, making it the fourth largest town in the county. The population peaked in 1830 at 260—notably more than half, 132, were slaves. With the incorporation of Middleburg the following year, Aldie began a slow decline.