John of Jerusalem was a Christian theologian who lived and worked in the late 5th and early 6th centuries CE. He was active during a period of intense religious debate following the Council of Chalcedon in 451 CE. His epithet suggests a strong connection to the city of Jerusalem, though the specific details of his life and ecclesiastical rank are not known.

He is historically significant as a defender of the Council's doctrine, which held that Christ existed in two natures, divine and human. This position was opposed by the Miaphysite (or anti-Chalcedonian) movement. John wrote to argue for this dyophysite view during the reign of Emperor Anastasius I, a time when the imperial court sometimes favored his theological opponents.

His major surviving work is a treatise titled Contra Monophysitas (Against the Monophysites). According to modern scholars, he is known to have written other works, but only this one treatise has been preserved, and it survives only in a Syriac translation. The existence of this Syriac version is considered important evidence for the cross-linguistic spread of theological debates in the late antique world, showing his arguments were engaged with beyond Greek-speaking circles.

John of Jerusalem's writings offer a window into the ongoing efforts to explain and defend Chalcedonian orthodoxy in the Eastern provinces of the Byzantine Empire long after the council itself.