Wat Si Saket is a Buddhist wat in Vientiane, Laos. It is situated on Lan Xang Road, at the corner with Setthathirat Road, to the northwest of Haw Phra Kaew.
Wat Si Saket was built in 1818 under the reign of King Anouvong (Sethathirath V.) Si is derived from the Sanskrit title of veneration Sri, prefixed to the name of Wat Saket in Bangkok. The temple architecture is also inspired by Thai style, which may have kept it safe as the Siamese sacked Vientiane in 1827 and used the compound as their Headquarters and lodging place.
Wat Si Saket is the oldest temple in Vientiane now. The temple features a cloister wall with more than 2000 ceramic and silver Buddha images. A number of damaged statues half melted by the fire of 1828 are also on display.