Abu Bakr Muḥammad ibn al-Ṭayyib al-Bāqillānī (Arabic: أبو بكر محمد بن الطيب الباقلاني) was a famous Islamic scholar, theologian and logician who spent much of his life defending and strengthening orthodox Islam.
Born in Basra in 330/950, he spent most of his life in Baghdad, and studied theology under two disciples of al-Ash'ari, Ibn Mujahid al-Ta'i and Abu'l Hasan al-Bahili. He also studied jurisprudence under the Maliki scholars Abu Abdullah al-Shirazi and Ibn Abi Zayd al-Qayrawani. After acquiring expertise in both Islamic theology and Maliki jurisprudence he expounding the teachings of the Ash'ari school, and taught Maliki jurisprudence in Baghdad. He held the office of chief Qadi in Baghdad and in 'Ukbara, a town not far from the capital. al-Bāqillānī became a popular lecturer, and took part in debates with well-known scholars of the day. Because of his logical acumen and swift, unhesitating replies, the caliph 'Adud al-Dawla dispatched him as an envoy to the Byzantine court in Constantinople and he debated Christian scholars in the presence of their king in 371/981.