The Long Tong Festival, also called Hoi Xuong Dong, is a traditional festival of the Tay and Nung ethnic groups in the northern highlands of Vietnam.

The Long Tong Festival is the most important festival at the beginning of the new year, closely related to the wet rice culture. The festival is organized to express the wishes of the people for timely rains and favorable weather, abundant crops and prosperity. The festival also reflects the rich and diverse culture of the Tay and Nung people.

The Long Tong Festival is usually held from the 4th to the 25th day of the first lunar month in different places, such as Dinh Hoa district (Thai Nguyen province), Yen Son, Chiem Hoa, Na Hang districts (Tuyen Quang province), and Ba Be district (Bac Kan province). The exact date may vary depending on the local conditions and customs.