Barotac Viejo, officially the Municipality of Barotac Viejo (, , ), is a municipality in the province of Iloilo, Philippines. According to the , it has a population of people.
In 1957, the sitio of Poscolon in the barrio of Calaigang was converted into a barrio. The same law was reenacted in 1959, probably indicating resistance to the renaming.
Barotac Viejo is in the northern part of the Province of Iloilo, facing the strait of Guimaras and the island of Negros. It is bounded on the north by San Rafael, on the west by Banate, on the south by the Visayan Sea, and on the east by Ajuy. It is from Iloilo City and from San Rafael.
The total land area of .
A range of sprawling hills and high mountains occupy three quarters of the land of Barotac Viejo. Mount Agumid on the northern boundary with San Rafael is the highest mountain, at about 550 meters high.
The town is divided by a long mountain range into upper and lower regions. The upper region, about 1,000 feet above sea level, experiences cooler temperatures and more abundant rainfall. The lower region, located near the sea, is well populated and primarily dedicated to rice cultivation.
Barotac Viejo is served by two rivers, namely the Barotac Viejo River and the Barotac Cayo River, along with several creeks and springs.
The Barotac Viejo River is the longest and the widest river passing through the heart of the town. It never runs dry, although it occasionally overflows during heavy rains. The river is used for bathing, laundry, and fishing.
The municipality has approximately 10 miles of shallow shorelines, with nearby fishponds supporting local aquaculture.
Rainy season sets in about May and last up to the middle of January. The rainfall in the upper region is comparatively heavier than the lower region. This is due to the chain of high mountains surrounding the place and innumerable springs that flow along the foot of the hills the heaviest rainfall occurs about in the early part of September during the southwest monsoon. Under usual condition, Barotac Viejo receives up to of rainfall. The average however in the upper region is and in the lower region . Dry season sets in a little earlier in the lower region than in the upper region.
Barotac Viejo is politically subdivided into 26 barangays. Each barangay consists of puroks and some have sitios.
In the 2024 census, the population of Barotac Viejo was 49,736 people, with a density of .
The Barotac Viejo Schools District Office governs all educational institutions within the municipality. It oversees the management and operations of all private and public, from primary to secondary schools.