The surname of Williamson is an English, and Northern Irish name meaning "son of William." The Old German name is ‘William.’ The term wil which means ‘will’ or ‘desire’ was added with the term helm means ‘helmet’ or ‘protection.’ Other spellings or forms include Williams, Willson and Wilson. for Williamson individuals are England Ireland and Wales.

In England the Williamson families live in Lancashire, Yorkshire and the London area. For Scotland the Shetland Islands off the east coast are home to many with the Williamson surname. Also in Scotland the counties of Midlothian and Lanarkshire have many Williamson families.

States of Ohio, Virginia, York, California, North Carolina, Pennsylvania, Missouri, Texas, Mississippi, Alabama, Georgia, Kentucky, Tennessee and Illinois have many with the Williamson surname. In the 1880s Williamson families were farmers.

Famous: Charles Norris Williamson (19th century English writer and journalist and founder of Black and White Magazine), James C. Williamson (19th century -born actor-manager who founded a theatrical empire in Australia), Malcolm Williamson (Australian composer and former Master of the Queen's Music), Ned Williamson (19thcentury professional baseball player with Chicago White Stocking team and two World Series), Matthew Williamson (British fashion designer with east Indian influence), Billy Williamson (Scottish footballer, played in two Scottish League Cup Finals) and Alexander William Williamson (English-Scottish chemist known for developing Williamson ether synthesis).