Ali Masjid Fort (Pashto:علي مسجد فورټ; Urdu: علی مسجد فورٹ) is situated on a high location above Ali Masjid, the narrowest point of the Khyber Pass,^[1] in the Khyber Pakhtunkhwa province on the north west frontier of Pakistan.^[2]

Originally within Afghanistan, the fort was first constructed in 1837 under Emir Dost Muhammad Khan, and was the location for a number of conflicts between Afghan and British-led forces during the 19th century. The fort was captured by the British in 1839 during the First Anglo-Afghan War,^[3] and again in November 1878 during the Second Anglo-Afghan War at the Battle of Ali Masjid.^[4] In May 1879 the Khyber Pass was ceded to British control by the Treaty of Gandamak, after which the fort was within the British Raj.^[5] In 1947 it became a part of Pakistan.