Sasmuan, officially the Municipality of Sasmuan, formally known by its Spanish name Sexmoán, is a 4th class municipality in the province of Pampanga, Philippines. According to the 2020 census, it has a population of 29,076 people, making it the least populated municipality in the province.

Pampanga, officially the Province of Pampanga, is a province in the Central Luzon region of the Philippines. Lying on the northern shore of Manila Bay, Pampanga is bordered by Tarlac to the north, Nueva Ecija to the northeast, Bulacan to the east, Manila Bay to the central-south, Bataan to the southwest and Zambales to the west. Its capital is the City of San Fernando. Angeles City is the largest LGU, but while geographically within Pampanga, it is classified as a first-class, highly urbanized city and has been governed independently of the province since it received its charter in 1964.