Coordinates: 51°41′10″N 0°01′59″W / 51.686°N 0.0331°W / 51.686; -0.0331

Waltham Cross is the most southeasterly town in Hertfordshire, England. It is 12 miles from the City of London and immediately north of the M25 motorway, forming part of the Greater London Urban Area and London commuter belt. Part of Waltham Cross is located within Greater London.

It is bordered by Greater London to the south and Essex to the east. It is located south of Cheshunt, west of Waltham Abbey and immediately north of the London Borough of Enfield, with the southern section of the town bordering the M25 motorway and Freezywater. Although located just outside Greater London, the town forms part of the Greater London Urban Area. The Waltham Cross post town includes some northern sections of Enfield, including the Holmesdale Estate.

Waltham Cross formed part of the ancient parish of Cheshunt in the Hertford hundred of Hertfordshire. It formed part of Cheshunt Urban District from 1894 to 1974. In April 1974 the town together with Cheshunt and the Hoddesdon urban district councils merged to form the Borough of Broxbourne. The town takes its name from the Eleanor Cross which stands in its centre.