thumb|250px|Cross section and plan of the mosque published by [[Cornelius Gurlitt (art historian)|Cornelius Gurlitt in 1912]]
The Bayezid II Mosque () is an early 16th-century Ottoman imperial mosque located in Beyazıt Square in Istanbul, Turkey, near the ruins of the Forum of Theodosius of ancient Constantinople.
History
The Beyazid Mosque was commissioned by the Ottoman Sultan Bayezid II, and was the second large imperial mosque complex (or selatin mosque) to be erected in Istanbul after the conquest in 1453. The earlier imperial complex, the Fatih Mosque, was later destroyed by earthquakes and completely rebuilt in a different style. As a result, the Beyazid complex is the oldest imperial complex in Istanbul that is preserved in more or less its original form, making it of considerable historical and architectural significance.
The mosque was constructed between 1500 and 1505, with a külliye (religious and charitable complex) added immediately afterwards. This included a medrese (theological college), completed in 1507; a large hamam (bathhouse), completed some time before 1507; an imaret (soup kitchen); a caravanserai; and several mausolea including the türbe of Bayezid II himself.
The chief architect of the mosque is not directly known. Based on Ottoman documents that mention architects during Bayezit II's reign, 20th-century scholar Rıfkı Melül Meriç identified Yakubşah ibn Islamşah as the most likely architect.