The name Josselyn has its origins in the French language and can be traced back to the Middle Ages. It is believed to be a variant of the Old French name Joscelin, which itself is derived from the Germanic name Gauscelinus or Goscelinus, formed from the elements "gaus" meaning "spear" and "lind" meaning "serpent".

One of the earliest recorded instances of the name Josselyn can be found in the 12th century, when it was borne by Josselin de Courtenay, a French nobleman and one of the leaders of the Third Crusade. Another notable bearer of the name was Josselin de Vierzy, a French trouvère and poet from the 13th century.

In England, the name gained popularity during the Middle Ages and was sometimes anglicized as Jocelyn or Joselyn. One of the earliest recorded bearers of the name in England was Josselyn de Brakenburg, a Norman knight who fought alongside William the Conqueror in the Battle of Hastings in 1066.

Throughout history, several notable individuals have borne the name Josselyn. One of the most famous was Josselyn Percy (1305-1352), an English nobleman and military commander who played a prominent role in the Wars of Scottish Independence. Another notable bearer of the name was Josselyn Leventhorpe (c. 1470-1509), an English courtier and member of the Privy Council during the reign of Henry VII.

In the 17th century, the name Josselyn was borne by Josselyn Twisleton (c. 1615-1677), an English politician and member of Parliament during the English Civil War. Another notable bearer of the name from this period was Josselyn Bodley (c. 1630-1674), an English diplomat and traveler who wrote extensively about his travels in the Middle East.

The name Josselyn also has a rich literary history, with several authors and poets bearing the name. One of the most notable was Josselyn Fenton (1628-1690), an English poet and playwright who was a member of the Twickenham circle of poets. Another literary figure with the name was Josselyn Phillipps (1798-1879), an English novelist and travel writer.

While the name Josselyn has its roots in French and Germanic origins, it has been adopted and borne by individuals from various cultures and backgrounds throughout history, making it a truly global name with a rich and diverse heritage.