Muhammad Baqir ibn Muhammad Akmal al-Wahid Bihbahani, also Vahid Behbahani (1706–1791), was a Twelver Shia Islamic scholar. He is widely regarded as the founder or restorer of the Usuli school of Twelver Shi'a Islam and as playing a vital role in narrowing the field of orthodoxy in Twelver Shi'a Islam by expanding "the threat of takfir" against opposing scholars "into the central field of theology and jurisprudence".