The second half of the name, –ley, derives from Old English: leah meaning a woodland or clearing. In the 13th century, it appears as Horleia, Hornle and Hornly, and in 1428 as Horneele. In 1203, it is recorded as Horleg and in 1219 as Horlei. The first written record of Horley is a charter from the late-12th century, in which it appears as Horle.

Because of its position, it has good commuter links to London and other surrounding towns, with good rail links at the railway station and bus services at the bus station. It has its own economy that comprises business parks and a shopping centre with a long high street.

The county border with West Sussex is to the south with Crawley and Gatwick Airport close to the town. Horley is a town in the borough of Reigate and Banstead in Surrey, England, south of the towns of Reigate and Redhill.