Taal Volcano (IPA: [taʔal]; Tagalog: Bulkang Taal) is a large caldera filled by Taal Lake in the Philippines. Located in the province of Batangas about 50 kilometers (31 mi) south of Manila, the volcano is the second most active volcano in the country with 39 recorded historical eruptions, all of which were concentrated on Volcano Island, near the middle of Taal Lake. The caldera was formed by prehistoric eruptions between 140,000 and 5,380 BP.

Taal Volcano has had several violent eruptions in the past, causing deaths on the island and the populated areas surrounding the lake, with an overall death toll of about 6,000. Because of its proximity to populated areas and its eruptive history, the volcano was designated a Decade Volcano, worthy of close study to prevent future natural disasters. The site was declared National Geological Monument in 1998 and a national park in 2018.

Taal Volcano was known as Bombou or Bombon in the 1800s.

The municipality of Taal and the Taa-lan River (now known as Pansipit River) were named after the Taa-lan tree, which grows along the river. The tree also grew along the shore of Bombon Lake (now known as Taal Lake). The Taa-lan River was a narrow channel that connects the present-day Taal Lake and Balayan Bay to each other.

Taal is a Tagalog word in the Batangueño dialect that means true, genuine, and pure.

Taal Volcano is part of a chain of volcanoes lining the western edge of the island of Luzon. They were formed by the subduction of the Eurasian Plate underneath the Philippine Mobile Belt. Taal Lake lies within a 25–30 km (16–19 mi) caldera formed by explosive eruptions between 140,000 and 5,380 BP. Each of these eruptions created extensive ignimbrite deposits reaching as far away as present-day Manila.

Taal Volcano and Lake are entirely located in the province of Batangas. The northern half of Volcano Island falls under the jurisdiction of the lake shore town of Talisay, and the southern half in San Nicolas. The other communities that encircle Taal Lake include the cities of Tanauan and Lipa, and the municipalities of Talisay, Laurel, Agoncillo, Santa Teresita, San Nicolas, Alitagtag, Cuenca, Balete, and Mataasnakahoy.

Since the formation of the caldera, subsequent eruptions have created a volcanic island within the caldera, known as Volcano Island. This 5-kilometer (3.1 mi) island covers an area of about 23 square kilometers (8.9 sq mi) with the center of the island occupied by the 2-kilometer (1.2 mi) Main Crater with a single crater lake formed from the 1911 eruption. The island consists of different overlapping cones and craters, of which forty-seven have been identified. Twenty six of these are tuff cones, five are cinder cones, and four are maars. The Main Crater Lake on Volcano Island is the largest lake on an island in a lake on an island in the world. This lake used to contain Vulcan Point, a small rocky island inside the lake. After the 2020 eruption, the Main Crater Lake temporarily disappeared due to volcanic activity, but had returned by March 2020.