The Syriac Orthodox Church of Antioch (Syriac: ܥܺܕܬܳܐ ܣܽܘ̣ܪܝܳܝܬܳܐ ܬܪܺܝܨܰܬ ܫܽܘ̣ܒ̥ܚܳܐ), or Syriac Orthodox Patriarchate of Antioch and All the East, is an Oriental Orthodox church founded circa 512 by Patriarch Severus in Antioch, Byzantine Empire. Employing the Divine Liturgy of Saint James with Syriac as its official and liturgical language, it is part of the Syriac Christianity by heritage. The church is led by the Syriac Orthodox Patriarch of Antioch Ignatius Aphrem II since 2014, seated in Cathedral of Saint George, Bab Tuma, Damascus, Syria. The church is often referred to as Jacobite Syriac Orthodox Church (after Jacob Baradaeus), but it rejects this name.
The Syriac Orthodox Church belongs to the Oriental Orthodoxy, a distinct communion of churches since the schism following the Council of Chalcedon in 451.
Patriarch Severus of Antioch was a significant bishop in the establishment of the organisation of the Syriac Orthodox Patriarchate of Antioch, Byzantine Empire, around 512, while Bishop Jacob Baradaeus (died 578) is credited for consolidating its miaphysite theology in the 6th century. However, the church itself claims apostolic succession through the prior Patriarchate of Antioch to the first Christian communities established by Saint Peter in Antioch, Roman Empire, in 37, as described in the Acts of the Apostles (New Testament, Acts 11:26). Around 1665, many Saint Thomas Christians of Kerala, India, affirmed allegiance to the Syriac Orthodox Church, establishing the Malankara Syrian Church. In the Levant, controversy occurred in 1783, when the majority of its hierarchy entered in full communion with the Catholic Church, establishing the Syriac Catholic Church as part of the Eastern Catholic Churches. However, another part of clergy gained permission from the Ottoman authorities in Istanbul to reestablish the Syriac Orthodox Church soon after.