The Syriac Sinaiticus or Codex Sinaiticus Syriacus (syrs), known also as the Sinaitic Palimpsest, of Saint Catherine's Monastery, or Old Syriac Gospels is a late-4th- or early-5th-century manuscript of 179 folios, containing a nearly complete translation of the four canonical Gospels of the New Testament into Syriac, which have been overwritten by a vita (biography) of female saints and martyrs with a date corresponding to AD 697. This palimpsest is the oldest copy of the Gospels in Syriac, one of two surviving manuscripts that are conventionally dated to before the Peshitta, the standard Syriac translation.

Saint Catherine's Monastery, officially the Sacred Autonomous Royal Monastery of Saint Catherine of the Holy and God-Trodden Mount Sinai, is a Christian monastery located in the Sinai Peninsula of Egypt. Located at the foot of Mount Sinai, it was built between 548 and 565, and is the world's oldest continuously inhabited Christian monastery.