The Action at Mount Zion Church was a cavalry skirmish during the American Civil War that took place on July 6, 1864, between Union forces under Major William H. Forbes and Confederate forces under Colonel John S. Mosby near Aldie in Loudoun County, Virginia, as part of Mosby's Operations in Northern Virginia. After successfully raiding the Union garrison at Point of Rocks, Maryland, Mosby's Rangers routed Forbes's command, which had been sent into Loudoun County to engage and capture the Rangers.