Cape Santiago (Filipino: Cabo Santiago) is the southwestern point of the island of Luzon located within the municipality of Calatagan in Batangas, Philippines. It is a cape at the southern tip of Santiago Peninsula which faces the South China Sea to the west and Pagapas Bay, an arm of Balayan Bay, to the east. The cape has been the site of a navigational aid since the 1890s.
Cape Santiago is located about 6.8 kilometres (4.2 mi) southeast of the Port of Calatagan where ferries bound for Lubang Island operate. It is 91 to 116 meters high, wooded, and fringed by a drying reef extending 0.16 kilometres (0.099 mi) offshore. There are depths of 7 to 9 meters at the edge of the reef, increasing steeply to more than 91 meters about 0.8 kilometres (0.50 mi) offshore.  A dangerous coral rock lies 6.4 kilometres (4.0 mi) southeast of the cape in the Verde Island Passage known as Minerva Rock, named for the Australian ship that struck on it in 1834.
A lighthouse marks a low rocky promontory about 0.5 miles (0.80 km) west-northwest of the south extremity of the cape. A conspicuous windmill stands about 0.4 mile east-southeast of the lighthouse.
Cape Santiago Lighthouse
The lighthouse at Cape Santiago is the oldest structure in Calatagan built in the 1890s during the Spanish colonial period. Made of brick and lime cement, this red round structure is 51 feet (16 m) tall modeled after the medieval castles in Europe. It is currently in a deteriorated condition with its original light source missing, replaced by an automatic light bulb donated by the Japan International Cooperation Agency that is no longer being used due to lack of funding.
The area surrounding the lighthouse was slated for a resort development but did not materialize after its developer, the Resort Association of the Philippines, Inc. owned by former Batangas governor Antonio Leviste, was found in violation of environmental laws when it reclaimed some 9,000 square meters of sea area adjacent to the lighthouse. In October 2007, the Philippine Coast Guard Auxiliary proposed to adopt and restore the lighthouse as its headquarters.
- "U.S. Coast and Geodetic Survey. Philippine Islands Sailing Direction, Section 3". Manila Bureau of Printing. Retrieved 21 August 2014.
- "Military notes on the Philippines: September 1898". United States. Adjutant-General's Office. Military Information Division. Retrieved 21 August 2014.
- "Historical lighthouse in Calatagan needs rehabilitation". Philippine Daily Inquirer. 27 October 2007. Retrieved 21 August 2014.