Calabarzon (/ká-lɑ-bɑr-zon/), formally known as Southern Tagalog Mainland[2] and designated as Region IV-A, is anadministrative region in the Philippines. The region comprises five provinces: Cavite, Laguna, Batangas, Rizal, and Quezon; whose names form the acronym CALABARZON. Its regional center is Calamba in Laguna.

Situated just south of Metro Manila in southwestern Luzon, the region is the most populous in the Philippines, having 14,414,774 inhabitants in 2015, and is also the country’s second most densely populated.[1] Prior to its creation as a region, Calabarzon, together with Mimaropa, formed the historical region known as Southern Tagalog, until they were separated in 2002 by virtue ofExecutive Order No. 103.

The region is home to some of the most important Philippine historical figures, most notable of which is the Philippines’ national hero, Jose Rizal, who was born in Calamba.


Historical events occurring in the Calabarzon region date back as early as the year 900 with the appearance of the Laguna Copperplate Inscription, which referenced the cancellation of a debt as enforced by the Lakan of the Kingdom of Tondo. Natives in Batangas have populated the Pansipit River and have engaged in trade with China during the 13th century. The Southern Tagalog region was populated by independent villages composed of 50 to 100 families called barangays.

During the Spanish Era, the Philippines was divided into various provinces (alcadia governed by a provincial governor (alcalde mayor). By the time of the Philippine Revolution in 1898, the region that is now known as Calabarzon comprised the provinces of Cavite, Laguna (previously as La Laguna), Batangas, Morong (now named Rizal) and Tayabas (now named Quezon).

On June 5, 1901, a convention was called on whether or not the province of Manila should annex the province of Morong, which was found to be unable to be self-sufficient as a province. Eventually, on June 11, Act No. 137 of the First Philippine Commissionabolished Morong and created a new province, named after the Philippines’ national hero, Jose Rizal, who, coincidentally, was a native of Laguna. The new province comprised 29 municipalities, 17 from Manila and 12 from Morong. In 1902, Macario Sakay, a veteran Katipunan member, established the Tagalog Republic in the mountains of Rizal. Ultimately, Sakay’s Tagalog Republic ended in 1906 when he and his men were betrayed under the guise of holding a national assembly aimed at the self-determination of the Filipino people.[3]

On September 7, 1946, the Third Philippine Republic enacted Republic Act No. 14, which renamed the province of Tayabas toQuezon, in honor of Manuel Quezon. Quezon was the second President of the Philippines and a native of Baler (now part ofAurora). In 1951, the northern part of Quezon became the sub-province Aurora, named after Quezon’s wife.

On September 24, 1972, President Ferdinand Marcos enacted Presidential Decree No. 1, which organized the provinces into 11 regions as part of Marcos’ Integrated Reorganization Plan. The IRP created Region IV, known as the Southern Tagalog region, and was the largest region in the Philippines. At this time, Region IV consisted of Batangas, Cavite, Laguna, Marinduque, Oriental Mindoro, Occidental Mindoro, Quezon, Rizal, Romblon, and Palawan. In 1979, Aurora formally became a province independent of Quezon and was also included in Region IV.


Executive Order No. 103, dated May 17, 2002, made great changes to the Southern Tagalog region. Due to its size, Region IV was split into two separate regions, Region IV-A (Calabarzon) and Region IV-B (Mimaropa). Aurora was transferred to Region III, Central Luzon.

Executive Order No. 246, dated October 28, 2003, Former President Gloria Arroyo declared Calamba City as the regional center of the region.[4]

Administrative divisions

Calabarzon comprises five provinces, 1 highly urbanized city, 18 component cities and 4,011 barangays.

Province or HUC Capital Population (2015)[1] Area[5] Density Cities Muni. Bgy.
km2 sq mi /km2 /sq mi
Batangas Batangas City 18.7% 2,694,335 3,119.75 1,204.54 860 2,200 3 31 1,078
  • Imus (de jure)
  • Trece Martires (de facto)
25.5% 3,678,301 1,574.17 607.79 2,300 6,000 7 16 829
Laguna Santa Cruz 21.1% 3,035,081 1,917.85 740.49 1,600 4,100 6 24 674
Quezon Lucena 12.9% 1,856,582 8,989.39 3,470.82 210 540 1 39 1,209
Rizal Antipolo 20.0% 2,884,227 1,191.94 460.21 2,400 6,200 1 13 188
Lucena 1.8% 266,248 80.21 30.97 3,300 8,500 33
Total 14,414,774 16,873.31 6,319.77 850 2,200 19 124 4,011
 †  Lucena is a highly-urbanized city; figures are excluded from Quezon province.

The region has 19 cities (18 component cities and the highly urbanized city of Lucena). Antipolo is the seventh most populous city in the Philippines. A large section of Calabarzon is considered part of the Greater Manila Area; while Batangas City is home to the Batangas metropolitan area. Calabarzon has a gross regional product of ₱1.65 trillion (at current prices), which accounts for 17% of the national GDP.[6]

Special City
Name Population (2015)[1] Area Density City class Income class Province
Los Baños 112,008 54.22 km2
(20.93 sq mi)
(5,400/sq mi)
Special Science and Nature CityB 1st Laguna

A Antipolo was declared a “highly-urbanized city” by President Benigno Aquino; such proclamation however still needs to be ratified in a plebiscite.[8]
B On August 7, 2000, the municipality of Los Baños, Laguna was declared as a “Special Science and Nature City of the Philippines”[9][10] through Presidential Proclamation No. 349[11] in recognition of its importance as a center for science and technology, being home to many prestigious educational, environmental and research institutions. This proclamation does not convert the municipality to a city or give it corporate powers that are accorded to other cities.