The Tran Temple Festival is one of the major traditional festivals in Nam Dinh, Vietnam. It is held on the 15th day of the 8th lunar month in Loc Vuong, Nam Dinh.

The festival grounds consist of three main temples: Thien Truong Temple (Up Temple), Trung Hoa Temple (Center Temple), and Co Trach Temple (Down Temple). Thien Truong Temple was built on the site of the former Trung Quang Palace, where the Tran kings lived and worked.

The first aisle of Thien Truong Temple houses the altars and plaques of the Tran Dynasty mandarins. The other two aisles in the back are dedicated to the Tran kings and their ancestors. The altars of their queens are located on the sides of the interior. Co Trach Temple is dedicated to Tran Quoc Tuan, one of the most famous generals in Vietnamese history. He won three epic victories against the Mongol invaders during the Tran Dynasty.

The Tran Temple Festival is held at Thien Truong Temple in Loc Vuong ward in the northern province of Nam Dinh. The main ritual of the festival is the seal opening ceremony, which takes place on the 14th night of the first lunar month. People flock to the ceremony each year to pray for good luck and happiness.

The festival also features a water procession and fish worshiping rituals on the first day of the event. These rituals honor fishing during the times of the Tran dynasty.

Other activities during the Tran Temple Festival include lion dances, dragon dances, cheo (traditional opera) and chau van (spiritual) singing, human chess, wrestling, and martial arts performances.