Simeon of Beth Arsham (Syriac: ܫܡܥܘܢ ܕܒܝܬ ܐܪܫܡ, translit. Shemʿun di-Beth Arsham) was a Syrian bishop who spread his teachings at the beginning of the sixth century. He was the bishop of Beth Arsham (House of Arsames), which was located near Seleucia-Ctesiphon.
Simeon was known as an eloquent and passionate disputant, and devoted to his Orthodox faith. He used to argue with Nestorians, Manicheans, Eutychians and the doctrines of Marcion of Sinope and Bardaisan in which he earned the title 'The Persian Disputant'. He spent most of his life in Mesopotamia and Persia preaching Christianity, where many pagan Arabs, dignitaries of Persian Zoroastrianism and Magians were baptized by him. Three baptized Magi were denounced by the king Kavadh I and their former colleagues, they were found dead ten days after their baptism. According to John of Ephesus, Simeon was threatened with death and had to grow his hair and beard to go unnoticed.
An alliance broke out between the Nestorian Church and the Persian monarchy, the Nestorians presented themselves as the national Christian church and denounced their opponents as a "fifth column" of the Byzantine Empire. Simeon then made his first journey to Constantinople, and obtained a letter from the emperor Anastasius to be delivered to the king of the Persians, where he begged him not to take sides in the quarrels between the Christians of his state.