Don Guillermo Manabat, a rich landlord, is believed to be the founder of Bacolor.
Historical record show that Bacolor has been in existence as proposed settlement as early as 1571. When the Spaniard under the leadership of Ferdinand Blumentrit arrived they found "Baculud", its original name meaning level ground because Bacolor was formerly part of the Philippine coastline until eruptions from Ancestral Mt. Pinatubo raised it above the ocean floor, on october 1, 1995, the lahar flows from the mountain raised it to it's current level of an approximate 37 meters above sea level. Subsidy caused the constant reclaiming of parts of Pampanga by the Sea.
The first settlers of Bacolor were believed to be Malays that came from Atjeth Sumatra led by Panday Pira. It is believed to have been founded by Monmon, first cousin and sister-in-law of Malangsic, a son of Prince Balagtas. However, historians recorded the official foundation of Bacolor to have occurred in 1574 through a landlord named Guillermo Manabat, whose palatial house and resting place is now the site of the San Guillermo Church, hence the Church's name.
The name Baculud was change to Bacolor when the Spaniard came to the place. It was recorded to have been the first capital of Pampanga for two centuries (1698 to 1904) before San Fernando was declared the capital town of the province in July 1904. In 1757, the provincial building, Casa Real, was constructed at the place where the Bacolor Elementary School is now located.
During the British Occupation of the Philippines, when Manila fell to the British, it became capital of the exiled government of Governor General Simón de Anda y Salazar from October 6, 1762 to May 30, 1764. The provincial offices were temporarily moved to Factoria (now San Isidro, Nueva Ecija). It remained the former capital town of Pampanga until the provincial seat of government was transferred to neighboring City of San Fernando in 1904. Through a decree of the King of Spain on November 9, 1765, Bacolor became "Villa de Bacolor", one of the only three Villas in the Philippines and was granted a Spacial Coat of Arms. Simon de Anda organized an army of natives with which he finally recaptured Manila from the British invaders.
The coming of the American Colonizers broke up the military form of government and instead political and economic reforms were introduced. A civil form of government was organized and was inaugurate on February 13, 1901 by Com. William H. Taft which took place in the old "Escuala de Artes y Officios de Bacolor" (formerly named Pampanga School of Arts and Trade) now known as the Don Honorio Technological State University the first state university in Pampanga.
The first Provincial Civil Governor was Don Ceferino Joven and the first Municipal President of Bacolor was Don Estanislao Santos. Pampanga was acknowledged as the first province to have organized civil government in the Philippines by General Grant, the then President of the United State of America.
In 1956, the sitio of Mesalipit was converted into a barrio.
On the morning of October 1, 1995, over 20 feet (6.1 m) of Lahar from the slopes of Mount Pinatubo and surrounding mountains buried the entire town of Cabalantian among many others, killing hundreds of people. 18 out of the 21 barangays of Bacolor were buried.