Aldie is an unincorporated community and census-designated place located between Chantilly and Middleburg in Loudoun County, Virginia, United States. The historic village of Aldie is located on the John Mosby Highway in a gap between the Catoctin Mountains and Bull Run Mountains, through which the Little River flows. Aldie traditionally ser…Aldie is an unincorporated community and census-designated place located between Chantilly and Middleburg in Loudoun County, Virginia, United States. The historic village of Aldie is located on the John Mosby Highway in a gap between the Catoctin Mountains and Bull Run Mountains, through which the Little River flows. Aldie traditionally serves as the gateway to the Loudoun Valley and beyond.