The Crabb name is believed to have originated in Holland and Belgium. The Flemish came to Britain around 1150 AD migrating to Wales, Norfolk, Suffolk and Hertfordshire. The first references to the name Crabb were in Cambridgeshire, Norfolk and Somerset around 1273 where Crabb families were recorded as having estates and manors. Soon after this records show Crabbs moving north. A Flemish engineer, John Crabb, was recorded at the siege of Berwick.
The Flemish, and with them the Crabb family name, migrated from England to Australia, New Zealand, the Carolinas, Virginia , Nova Scotia, Newfoundland and the West Indies. In North America a John Crabb settled in Boston in 1630. During the American War of Independence, many loyalists went north to Canada around 1790 to become United Empire Loyalists.
The spelling of the name varied even within families - Crabb, Crabbe, Crab and Crabe are common variations.