There are multiple origins for the surname Gorman. The Irish name is an Anglicised form of the Gaelic Mac Gormáin and Ó Gormáin, meaning "son of Gormán" and "descendant of Gormán". The personal name Gormán is derived from the diminutive of gorm, meaning "dark blue", "noble". One English origin of the name is from the Middle English personal name Gormund (Old English Garmund). This name is made up of the elements gar "spear" + mund "protection". The English surname Gorman can also be a topographic name for someone who lived near a triangle piece of land. The German surname (Görmann) is sometimes a variant of Gehrmann. German Gorman can also be of Slavic origin, from a occupational name, derived from the Slavic góra meaning "mountain".
Early bearers of the surname are William Gorman in 1296 and Adam Garman in 1327. The John atte Gore recorded in 1296 within the Sussex Subsidy Rolls is identical with the John Gorman recorded in 1332.