The Jesus bloodline refers to the proposition that a lineal sequence of the historical Jesus has persisted, possibly to the present time. The claims frequently describe Jesus as having married, often to Mary Magdalene, and as having descendants living in Europe, especially France but also the UK. Differing and contradictory Jesus progeny scenarios, as well as more limited claims that Jesus married and had children, have been proposed in numerous modern books. Some such claims have suggested that Jesus survived the crucifixion and went to another location such as France, India or Japan.

The Prieuré de Sion, translated as Priory of Sion, was a fraternal organization founded in France in 1956 by Pierre Plantard in his failed attempt to create a prestigious neo-chivalric order. In the 1960s, Plantard began claiming that his self-styled order was the latest front for a secret society founded by crusading knight Godfrey of Bouillon, on Mount Zion in the Kingdom of Jerusalem in 1099, under the guise of the historical monastic order of the Abbey of Our Lady of Mount Zion. As a framework for his grandiose assertion of being both the Great Monarch prophesied by Nostradamus and a Merovingian pretender, Plantard further claimed the Priory of Sion was engaged in a centuries-long benevolent conspiracy to install a secret bloodline of the Merovingian dynasty on the thrones of France and the rest of Europe. To Plantard's surprise, all of his claims were fused with the notion of a Jesus bloodline and popularised by the authors of the 1982 speculative nonfiction book The Holy Blood and the Holy Grail, whose conclusions would later be borrowed by Dan Brown for his 2003 mystery thriller novel The Da Vinci Code.