Saint Josaphat is said to have lived and died in the 3rd century or 4th century in India. His story appears to be in many respects a Christianized version of Siddhartha Gautama's story. His name derives from the Sanskrit term bodhisattva via the Middle Persian bodasif. He was popular in the Middle Ages, principally as part of a Christian usage of a Buddhist story about Siddhartha, along with another legendary saint, Saint Barlaam.

Wilfred Cantwell Smith traced the story from a second to fourth-century Sanskrit Mahayana Buddhist text, to a Manichee version, to an Arabic Muslim version, to an eleventh century Christian Georgian version, to a Christian Greek version, and from there into Western European languages.

He should not be confused with Saint Josaphat Kuncevyc; nor should Saint Barlaam be confused with Saint Barlaam of Calabria.

See also: List of saints