Dictionary of Irish Family Names

by Ira Grehan pages 39-40 BRYANT

surname was originally BRYAN, no connectoin with any Irish name. A popular family name in rural Brittany, came to England when the Bretons joined the Normans-conquest of England 1066. Up until the nineteenth century, Bryant's were found mainly in north of England: Yorkshire, Westmoreland & Furness. Probably arrived in Ireland with armies of the Commonwealth, not in any great numbers. Only about a couple dozen found in Ireland toay. Bryan much more common surname.
Sir Arthur Bryant was one of England's most distinguished twentieth-century historians. Bryant name well-presented in army & navy lists. Retired Rear Admiral Bryant managed a Rolls-Royce in Scotland. But the most outstanding Bryants are in the USA. WILLIAM CULLEN BRYANT 1794-1878: barrister, politician, forged new frontiers in poetry, and wrote a number of travel books.