Joselin is a feminine given name that originated in the Middle Ages as a variant of the French name Joseline, which itself is a derivative of the masculine name Joseph. The name Joseph has Hebrew origins, stemming from the phrase "Yoseph-el," meaning "he will add" or "may he add."

The earliest recorded use of the name Joselin dates back to the 12th century in France, where it was a popular name among the nobility. One notable bearer of the name was Joselin de Vierzy, a 12th-century poet and trouvère from the Champagne region of France.

During the 13th century, the name Joselin gained popularity in England, possibly due to the influence of French culture brought by the Norman conquest. One of the earliest recorded English bearers of the name was Joselin de Munchensi, a 13th-century nobleman and landowner who served as High Sheriff of Wiltshire.

In the 14th century, the name Joselin appeared in religious texts, such as the "Golden Legend," a collection of hagiographies written by Jacobus de Voragine. The text mentions a Saint Joselin, although little is known about her historical significance.

Throughout history, several notable individuals have borne the name Joselin. One such person was Joselin de Blanquefort, a 14th-century French knight who fought in the Hundred Years' War. Another was Joselin de Cassanhis, a 15th-century French diplomat and scholar who served as the ambassador of the Duke of Burgundy to England.

In the 16th century, the name Joselin was borne by Joselin de Marles, a French Renaissance poet and writer who was a member of the Pléiade literary movement. A century later, Joselin de Châtellier was a 17th-century French noblewoman and courtier who served as a lady-in-waiting to Queen Marie de' Medici.

Despite its historical significance, the name Joselin has become relatively uncommon in modern times, although it continues to be used occasionally in France and other French-speaking regions.