Wat That Thong is a royal monastery and funeral temple in Bangkok's Sukhumvit area, of which construction was started in 1938 by combining the names of two existing and historically related temples from elsewhere in the city, namely Wat Na Phra That and Wat Thong Lang, to become Wat That Thong. The wisung khama sima, i.e. the royal granting of the land to have the temple constructed, which materializes in the presenting of the consecrated boundary foundation stone of the ordination hall, was bestowed by King Rama VIII on 24 October 1940.

In 2007, Princess Galyani Watthana took the temple under her patronage and consequently presented a new logo, with her personal seal bearing her initials (fig.), to the monastery. The ordination hall seen here was built in 1952.

The Phra prathaan, i.e. the principal Buddha image, is housed in the ubosot, is known as Phra Suppanyu. The statue is seated in the half lotus position and depicted with a bhumisparsa mudra. In front of this principal Buddha image are several other Buddha statues.

To the left is the gilded Phra Phutta Chinintara image, seated in the maravijaya pose, to the right is the gilded Luang Pho Phra Phutta Abhipala Puang Chon image, depicted in the pastoral care pose, whilst in between them is the bonze Phra Phutta Monthon Preecha Sukhothai image, also seated in the maravijaya pose.

There is also a chedi that contains relics of the Buddha. Though most Buddhist temples in Thailand have a crematorium, some temples in larger cities, such as this one, focus primarily on the organization of funerals, on an almost industrial scale.

This goes from the services held by monks for the relatives to the cremation of the remains, up to the storage of the ashes in sepulchral vaults in a special corner on the temple's compound.

On 29 May 2012, King Bhumipol Adulyadej, i.e. Rama IX, raised the monastery's level to a third class royal temple.