Yunnan, a southwestern frontier province in China is located in mainland Southeast Asia and is inhabited by diverse cross-regional ethnic groups. This essay attempts to reveal the Bengal connections in historical Yunnan from the medieval age to the early modern period through a scrutiny of Chinese and certain non-Chinese sources. It fi rst discusses the use of cowry currency in Yunnan and other areas around the Bay of Bengal, and then constructs historical routes linking the Bengali world and Yunnan, both by land and sea. Furthermore, the spread of Buddhism into Yunnan is highlighted to demonstrate Bengali cultural infl uence. The Bengal connections in Yunnan hence, shed some light on both historical Yunnan and the formation of Chinese frontiers.