The Bengal Sultanate (Middle Bengali: শাহী বাঙ্গালাহ্, Classical Persian: سلطنت بنگاله) was a late medieval sultanate based in the Bengal region in eastern South Asia between the 14th and 16th century. It was the dominant power of the Ganges-Brahmaputra Delta, with a network of mint towns spread across the region. The Bengal Sultanate had a circle of vassal states in the Indian subcontinent and Southeast Asia, including parts of Odisha in the southwest, parts of Bihar in the northwest, parts of Assam in the northeast, Arakan in the southeast, and Tripura in the east.

The Bengal Sultanate controlled large parts of eastern South Asia during its five dynastic periods, reaching its peak under Jalaluddin Muhammad Shah. Its raids and conquests reached Nepal in the north, Brahmaputra Valley (modern-day Assam) in the east, and Jaunpur and Varanasi in the west. It was reputed as a thriving trading nation. Its decline began with an interregnum by the Sur Empire, followed by Mughal conquest and disintegration into petty kingdoms. The Bengal Sultanate was a Sunni Muslim monarchy with Bengali, Turco-Persian, Afghan and Abyssinian elites. The most prominent dynasties were the Ilyas Shahi, House of Ganesha and Hussain Shahi. The kingdom was known for its religious pluralism where non-Muslim communities co-existed peacefully. While Persian was used as the primary official, diplomatic and commercial language, it was under the Sultans that Bengali first received court recognition as an official language. The cities of the Bengal Sultanate are termed as Mint Towns where the historical taka was minted. These cities were adorned with stately medieval buildings. In 1500, the royal capital of Gaur was the fifth-most populous city in the world. Other notable cities included the initial royal capital of Pandua, the economic hub of Sonargaon, the Mosque City of Bagerhat, and the seaport and trading hub of Chittagong. The Bengal Sultanate was connected to states in Asia, Africa, the Indian Ocean, and Europe through maritime links and overland trade routes. The Bengal Sultanate was a major trading center on the coast of the Bay of Bengal. It attracted immigrants and traders from different parts of the world. Bengali ships and merchants traded across the region, including in Malacca, China, and the Maldives.

Contemporary European and Chinese visitors described the Bengal Sultanate as a prosperous and thriving kingdom. Due to the abundance of goods in Bengal, the region was described as the "richest country to trade with". The Bengal Sultanate left a strong architectural legacy. Buildings from the period show foreign influences merged into a distinct Bengali style. The Bengal Sultanate was also the largest and most prestigious authority among the independent medieval Muslim-ruled states in the history of Bengal.

Bengal was gradually absorbed into the Delhi Sultanate during the 1200s. It began with Bakhtiyar's 1202–1204 conquest of Gauda during the reign of Muhammad of Ghor. This saw the beginning of the rise of Turko-Afghans in the Indian subcontinent. Bakhityar Khalji served as a military general of the Ghurid ruler Muhammad of Ghor. He formed the Khalji dynasty of Bengal. After the assassination of Bakhtiar Khalji by his own officer Ali Mardan in 1206, Bengal was administered by various Maliks belonging to the Khalji tribe (except a brief interregnum by Ali Mardan himself) until Delhi Sultan Iltutmish sent forces under his son, Nasir-ud-din Mahmud, to bring Bengal under the direct control of the Delhi Sultans. Iltutmish declared Bengal as a province of Delhi in 1225. The Delhi Sultans attempted to govern Bengal through appointed governors, however, Delhi could not succeed given the considerable overland distance with Bengal. Ambitious governors rebelled and ruled as independent rulers until being suppressed militarily by the Delhi Sultanate. However, there were capable rulers among the rebels, including Yuzbak Shah (1257), Tughral Khan (1271–1282), and Shamsuddin Firoz Shah (1301–1322). The latter achieved the Conquest of Sylhet and established a strong administration in eastern and south-western Bengal. In 1325, the Delhi Sultan Ghiyath al-Din Tughluq reorganized the province into three administrative regions, with Sonargaon ruling eastern Bengal; Gauda ruling northern Bengal; and Satgaon ruling southern Bengal. Even this arrangement broke down. By 1338, the three administrative regions had separatist Sultans, including Fakhruddin Mubarak Shah in Sonargaon; Alauddin Ali Shah in Gauda, and Shamsuddin Ilyas Shah in Satgaon. Fakhruddin conquered Chittagong in 1340 and was succeeded by his son Ikhtiyaruddin Ghazi Shah in 1349. Shamsuddin Ilyas Shah (or just Ilyas Shah) defeated Alauddin Ali Shah and secured control of Gauda. He then defeated Ikhtiyaruddin of Sonargaon. By 1352, Ilyas Shah emerged victorious among the Bengali triad.^{[citation needed]}

Ilyas Shah established his capital in Pandua. He unified the delta of Ganges, Brahmaputra and Meghna Rivers into the Sultanate of Bengal. Ilyas Shah waged wars and raids against several city-states and kingdoms in the eastern subcontinent. He conquered eastern Bengal and northern Bihar. He led the first Muslim army into Nepal, raided the Kathmandu Valley, and returned to Bengal with treasures. He controlled an area stretching from Assam in the east to Varanasi in the west. In 1353, Ilyas Shah was defeated by Delhi Sultan Firuz Shah Tughluq in the Siege of Ekdala Fort during the Ekdala Wars. Bengal agreed to pay a tribute to the Delhi Sultan. Despite losing control of many conquered areas, Ilyas Shah remained in firm control of Bengal.

Ilyas Shah founded the Ilyas Shahi dynasty which ruled Bengal for fifteen decades. His son and successor Sikandar Shah defeated Delhi Sultan Firuz Shah Tughluq during the second Siege of Ekdala Fort in 1359. A peace treaty was signed between Delhi and Bengal, with the former recognizing the independence of the latter. Firuz Shah Tughluq gave a golden crown estimated to be worth 80,000 taka to Sikandar Shah. The peace treaty ensured Bengal's independence for two centuries.

Sikandar Shah's reign lasted three decades. The Adina Mosque was built during his reign. The mosque's design was based on the Great Mosque of Damascus, style used during the introduction of Islam in new areas. During this time, much of the agricultural land was controlled by Hindu zamindars, which caused tensions with Muslim taluqdars.

The third Sultan Ghiyasuddin Azam Shah began expanding Bengal's influence abroad. He began to send embassies to Ming China, which continued as a tradition during the reigns of his successors. Ghiyasuddin also sponsored construction projects in Arabia. He exchanged letters and poetry with the Persian poet Hafez. The Bengal Sultans pledged nominal allegiance to the Abbasid Caliphate in Cairo. The coins of the Bengal Sultans often bore the name of the contemporary Abbasid Caliph. Ghiyasuddin Azam Shah held his court in the central Bengali city of Sonargaon, in addition to Pandua. The travel accounts of Chinese envoys state that the Sultan lived in a palace near the river port of Sonargaon. The river port had shipping links to China, Southeast Asia, and the Middle East. In 1406, Ma Huan found Sonargaon as a large metropolis. Other Chinese envoys provided descriptions of a fortified walled city. Sonargaon was a center of Sufi education and Persian literature and Azam Shah even invited Hafez to settle there. The institutions founded by Abu Tawwama during the Delhi Sultanate were maintained by his successors in the Bengal Sultanate, including the Sufi preachers Ibrahim Danishmand, Saiyid Arif Billah, Muhammad Kamel, Saiyid Muhammad Yusuf and others.