The name Joselyn is a feminine given name with roots in the French and English languages. It is derived from the Hebrew name Joseph, which means "he will add" or "he will increase." The name Joseph has a rich biblical history, as it was the name of the son of Jacob and Rachel in the Old Testament.

In French, the name Joselyn evolved from the Old French form Joseline, which was a diminutive or pet form of the name Joseph. This French variant later made its way into English as Joselyn. The earliest recorded use of the name Joselyn dates back to the 13th century in England.

One of the earliest known historical references to the name Joselyn can be found in the Domesday Book of 1086, where a landowner named Joselyn is mentioned. In the 12th century, there was a Norman knight named Joselyn de Courtenay who fought in the Third Crusade.

During the Middle Ages, the name Joselyn was particularly popular among the nobility and aristocracy in both England and France. One notable example is Joselyn de Bohun (c. 1208-1265), a wealthy English noblewoman and heiress who inherited significant landholdings.

In the 16th century, Joselyn Pearle (1536-1616) was an English musician and composer who served as a lutist and viol player at the court of Queen Elizabeth I. Another notable figure from this period was Joselyn Percy (1508-1572), an English nobleman and politician who served as Lord President of the Council of the North.

In the 17th century, Joselyn Shirley (1599-1646) was an English poet and playwright who wrote several masques and plays during the reign of King Charles I. Joselyn Mounteney (1609-1676) was an English clergyman and academic who served as the Vice-Chancellor of the University of Cambridge.

While the name Joselyn has French and English origins, it has also been used in other cultures and languages over time, often as a variant spelling or adaptation of the name Joseph or its feminine forms.