Redbourn is a village and civil parish in Hertfordshire, England, lying on Watling Street, three miles (4.8 km) from Harpenden, four miles (6.4 km) from St Albans and five miles (8 km) from Hemel Hempstead. The civil parish had a population of 5113 according to the 2011 Census.

The three tiers of local government are Redbourn Parish Council, St Albans City & District Council and Hertfordshire County Council.

To the south-west of the village, just beyond the motorway is the site of an Iron Age hill fort called the Aubreys. Nearby is Aubrey Park which dates back to the 13th Century. To the north of the village is the site of a complex of Roman temples.

The village has been continuously settled at least since Saxon times and is recorded in the Domesday Book. Its parish church, St Mary's, was built in the early 12th century. Some fifty years later, a small priory was founded half a mile away on Redbourn Common, after the abbot of St Albans Abbey decided to consecrate the ground. Some bones had been found on the spot, reputed to be of St Amphibalus, the priest who had converted St Alban to Christianity.

In the 16th century the manor of Redbourn belonged to the Reade family: Sir Richard Reade, formerly Lord Chancellor of Ireland, bought the manor when he came back to England from Ireland; he died in 1575 and was buried at the parish church. Reade left legacies to Winchester College and for the upkeep of the parish of Redbourn. The manor of Redbourn itself was inherited by his eldest son Innocent, who also inherited the older family estate at Nether Wallop.

In 2010, Redbourn's St Mary's Church celebrated its 900th anniversary.

The Hertfordshire County Show takes place annually in late May at a 70-acre show ground site one mile north of the village.

Redbourn was Hertfordshire Village of the Year, 2002 (Overall and Western Area Winner), and a section winner in 2003. In 2002 Redbourn was also an Eastern and Home Counties Section Winner. The year 2004 saw Redbourn again winning Hertfordshire Village of the Year, Western Area, and in 2005 it was the Hertfordshire Village of The Year IT Section Winner and Eastern England Information Communication Technology Winner 2005, also winner of the Hertfordshire Village of the Year Best Community Project Award, and the Silver Award Anglia in Bloom 2005.