Mar Shemʿon IV Basidi (died 20 February 1497) was the patriarch of the Church of the East in the last quarter of the 15th century. Traditionally his reign is said to have begun in 1437, but this results in an improbably long tenure and has been revised by modern research. Thomas Carlson puts the start of his reign in 1477, while David Wilmshurst places it about 1450. Shemʿon died on 20 February 1497 and was buried in the monastery of Rabban Hormizd near Alqosh, where he may have spent most of his patriarchate. An epitaph records his burial.