Jocelyn is a surname and first name. It is a unisex (male/female) name. Variants include Jocilyn, Joscelyn, Joscelin, Josceline, Jocelin, Jocelyne, Jocelynne, Jocelynn, Joslin, Joslyn, Joclyn, Joselyn, Joselyne and Josslyn; people that have this name may find it is often misspelled by others. The name may derive from Josselin in Brittany, France and was introduced to England after the Norman Conquest. It may also derive from the Germanic name Gauzlin, also spelled Goslin.
In French, the spelling "Jocelyn" is exclusively male. The female counterpart is spelled "Jocelyne".
The Irish name Oisdealbh was originally a translation of Jocelyn, to gaelicize Jocelyn de Angulo's given name. His Ireland-based descendants bore the surname Mac Oisdealbhaigh (son of Oisdealbh), which is better known in its anglicized form Costello.