The Festival of Māzŭ is the celebration of the Taoist goddess Māzŭ. The festival is held annually on the 23rd day of the third month of the Chinese calendar. It falls either in late April or early May in the Gregorian calendar.

This festival is particularly important to Chinese costal or island communities, reflecting Māzŭ's affinity with the sea. The Cantonese, Fujianese and Taiwanese peoples are foremost in celebrating this day. In Cantonese, Māzŭ is known as Tin Hau.