Wat Saket Ratchawora Mahawihan (Thai: วัดสระเกศราชวรมหาวิหาร), usually shortened to Wat Saket, is a Buddhist temple (wat) in Pom Prap Sattru Phai district, Bangkok, Thailand.

The temple dates back to the Ayutthaya era, when it was known as Wat Sakae (วัดสะแก). When Bangkok became the capital, King Rama I (1737–1809) renovated the temple and gave it its present name (which roughly translates as "wash hair"); it was believed that on his return from the war, the king stopped to take a bath and wash his hair here, before entering the inner city.