The Greenslade surname originates from the south west of England; it appears as a locational name in the Domesday census records of the 11th century. Today, there are still concentrations of Greenslades in Devon and Somerset, but other Greenslades have spread globally and especially to the New World: US, Canada, Australia and New Zealand.

The name is derived from Anglo-Saxon terms for a green open area within a wood (a clearing).