Mar Ishodad of Merv of Assyria (Syriac: ܡܪܝ ܝܫܘܥܕܕ ܐܦܣܩܘܦܐ ܕܚܕܬܐ ܕܒܐܬ̣ܘܪ) (fl. 850 AD) was a bishop of Hdatta and a prominent theologian of the Church of the East.
Not very much is known about his early life but he appears to have been born in Merv in Khorasan. He became a bishop of Hdatta. He was a candidate for the patriarchy of the Church of the East around 852 after the death of Abraham II. He is most renowned for his extensive Syriac exegesis of the Old and New Testaments.
He died shortly after 852 AD.