Barley is a village and civil parish in the district of North Hertfordshire, England. According to the 2001 census, it has a population of 659. The place-name refers to a lea or meadow and not to the grain-producing plant. Coincidentally to the southwest lies the village of Reed. The Prime Meridian passes to the west of Barley.
Located on the Royston to Saffron Walden road, as well as the medieval London to Cambridge road, Barley has a church with a 12th-century Norman tower, and dedicated to St Margaret of Antioch. The church was rebuilt in 1872 using designs by William Butterfield retaining only the tower and the fourth aisle.