Sasmuan, officially the Municipality of Sasmuan (Kapampangan: Balen ning Sasmuan, Tagalog: Bayan ng Sasmuan), formerly known by its Spanish name Sexmoán (pronunciation: ses-mo-wan), is a 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.

It was known as Sexmoan until January 15, 1991. The town's former name in Spanish was Sexmoán, as was initially transcribed by Spanish friars. In Spanish, the letter <x> used to be pronounced as a voiceless postalveolar fricative /ʃ/, identical to the digraph "sh" in English. It was derived from the ancient Kapampangan root word sasmo, which means to meet, according to a 17th-century Kapampangan dictionary. Sasmuan therefore is synonymous with "pitagmuan" or "meeting place of the datus" or "meeting point". It was named "Sasmuan" because it is where the Pampangos meet when they were at war with the Chinese in Guagua. In 1991, the spelling was unanimously changed into Sasmuan, due to perceived sexual connotations.

Sasmuan already had a well-developed system of government well before the era of Spanish colonization. It was one of the major towns of Pampanga in the 16th century.

The Santa Lucia Church was one of the first Roman Catholic churches built in the Philippines by the Spaniards with the political and financial support of the Principalia.

Sasmuan is located in the southern part of Pampanga. It is bounded to the north by the municipalities of Guagua and Minalin; to the east by the municipality of Macabebe; to the west by the municipality of Lubao; and to the south by Manila Bay. Most of the town's area is fish ponds. It is one of the three coastal towns in Pampanga along with Lubao and Macabebe.

Sasmuan is politically subdivided into 12 barangays. Each barangay consists of puroks and some have sitios.

Population census of Sasmuan

Year Pop. ±% p.a. 1903 6,981 —     1918 7,224 +0.23% 1939 10,018 +1.57% 1948 9,804 −0.24% 1960 13,081 +2.43% 1970 16,792 +2.53% 1975 16,849 +0.07% 1980 17,901 +1.22%	Year Pop. ±% p.a. 1990 21,148 +1.68% 1995 23,146 +1.71% 2000 23,359 +0.20% 2007 26,630 +1.82% 2010 27,254 +0.85% 2015 28,004 +0.52% 2020 29,076 +0.74%
Source: Philippine Statistics Authority

In the 2020 census, the population of Sasmuan, Pampanga, was 29,076 people, with a density of 320 inhabitants per square kilometre or 830 inhabitants per square mile.

Poverty incidence of Sasmuan

5 10 15 20 2006 12.10 2009 11.45 2012 6.73 2015 15.88 2018 6.07 2021 14.61 Source: Philippine Statistics Authority

Sasmuan has a unique geography in that it is surrounded by fish ponds. Aquaculture has been the main industry that drives the local economy. The fish from ponds and other areas are sold at the Fish Port.

The town has 2 prime business ventures and both are in the food industry. These two are Sasmuan Delicacies which was founded in 1990 and Aiza's Sweets which was started in 2000. For Sasmuan Delicacies, their products are being sold in many big supermarkets and malls in the Philippines, including SM City Malls. Aiza's Sweets on the other hand, has SM City Malls as one of their primary customer, but they also sell to several popular local shops such as Susie's Sweets, Nathaniels, etc. Also, Aiza's Sweets exports to the United States and Canada.

The Santa Lucia Parish Church in Sasmuan is the first church in the province built by Augustinian priests. It stands right beside the Río Grande, a river that connects Pampanga to Manila Bay. The structure is said to have been built by Jose Duque in the 17th century, was rebuilt in the early 1800s, and was reinforced by Toribio Fanjul in 1884.

The edifice has decorative floral carvings on its main entrance. The old town church is one of the few, if not the only church in the country where the single belfry is situated between the church and the convento. The church, which measures 45 metres (148 ft) long, 11 metres (36 ft) wide, and 6 metres (20 ft) high, also features a grotto of Our Lady of Fatima. Devotees from all over the province flock here to honor Saint Lucy, believed to be a miraculous saint.

Founded in 1590, Santa Lucia is a parish of the Vicariate of St. Joseph in the Archdiocese of San Fernando. The parish celebrates the feast day of its titular patron on December 13.

• Jose Montemayor Jr., a candidate for the 2022 Philippine presidential election.
• Japeth Aguilar, Filipino basketball player

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  Welcome Marker at Lubao-Sasmuan Road
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  St. Lucy School of the Archdiocese of Pampanga
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  Covered court and gymnasium

• List of renamed cities and municipalities in the Philippines
• Place names considered unusual

• Sasmuan Profile at PhilAtlas.com
• Philippine Standard Geographic Code
• Philippine Census Information
• Local Governance Performance Management System Archived 2016-03-03 at the Wayback Machine