The Japanese occupation of the Philippines (Filipino: Pananakop ng mga Hapones sa Pilipinas; Japanese: , romanized: Nihon no Firipin Senry) occurred between 1942 and 1945, when Imperial Japan occupied the Commonwealth of the Philippines during World War II.

The invasion of the Philippines started on 8 December 1941, ten hours after the attack on Pearl Harbor. As at Pearl Harbor, American aircraft were severely damaged in the initial Japanese attack. Lacking air cover, the American Asiatic Fleet in the Philippines withdrew to Java on 12 December 1941. General Douglas MacArthur was ordered out, leaving his men at Corregidor on the night of 11 March 1942 for Australia, 4,000 km away. The 76,000 starving and sick American and Filipino defenders in Bataan surrendered on 9 April 1942, and were forced to endure the infamous Bataan Death March on which 7,00010,000 died or were murdered. The 13,000 survivors on Corregidor surrendered on 6 May.

Japan occupied the Philippines for over three years, until the surrender of Japan. A highly effective guerrilla campaign by Philippine resistance forces controlled sixty percent of the islands, mostly forested and mountainous areas. MacArthur supplied them by submarine, and he sent reinforcements and officers. The Filipino population remained generally loyal to the United States, partly because of the American guarantee of independence, because of the Japanese mistreatment of Filipinos after the surrender, and because the Japanese had pressed large numbers of Filipinos into work details and put young Filipino women into brothels.General MacArthur kept his promise to return to the Philippines on 20 October 1944. The landings on the island of Leyte were accompanied by a force of 700 vessels and 174,000 men. Through December 1944, the islands of Leyte and Mindoro were cleared of Japanese soldiers. During the campaign, the Imperial Japanese Army conducted a suicidal defense of the islands. Cities such as Manila were reduced to rubble. Around 500,000 Filipinos died during the Japanese Occupation Period.

The Philippines ( (listen); Filipino: Pilipinas), officially the Republic of the Philippines (Filipino: Republika ng Pilipinas), is an archipelagic country in Southeast Asia. It is situated in the western Pacific Ocean, and consists of about 7,640 islands, that are broadly categorized under three main geographical divisions from north to south: Luzon, Visayas, and Mindanao. The Philippines is bounded by the West Philippine Sea to the west, the Philippine Sea to the east, and the Celebes Sea to the southwest, and shares maritime borders with Taiwan to the north, Japan to the northeast, Palau to the east and southeast, Indonesia to the south, Malaysia to the southwest, Vietnam to the west, and China to the northwest. The Philippines covers an area of 300,000 km2 (120,000 sq mi) and, as of 2020, had a population of around 109 million people, making it the world's thirteenth-most populous country. The Philippines is a multinational state, with diverse ethnicities and cultures throughout its islands. Manila is the nation's capital, while the largest city is Quezon City, both lying within the urban area of Metro Manila.

Negritos, some of the archipelago's earliest inhabitants, were followed by successive waves of Austronesian peoples. Adoption of animism, Hinduism and Islam established island-kingdoms called Kedatuans, Rajahnates and Sultanates. The arrival of Ferdinand Magellan, a Portuguese explorer leading a fleet for Spain, marked the beginning of Spanish colonization. In 1543, Spanish explorer Ruy López de Villalobos named the archipelago Las Islas Filipinas in honor of Philip II of Spain. Spanish settlement through Mexico, beginning in 1565, led to the Philippines becoming part of the Spanish Empire for more than 300 years. During this time, Catholicism became the dominant religion, and Manila became the western hub of trans-Pacific trade. In 1896, the Philippine Revolution began, which then became entwined with the 1898 Spanish–American War. Spain ceded the territory to the United States, while Filipino revolutionaries declared the First Philippine Republic. The ensuing Philippine–American War ended with the United States establishing control over the territory, which they maintained until the Japanese invasion of the islands during World War II. Following liberation, the Philippines became independent in 1946. Since then, the unitary sovereign state has often had a tumultuous experience with democracy, which included the overthrow of a dictatorship by the People Power Revolution.

It is considered to be an emerging market and a newly industrialized country, which has an economy transitioning from being based on agriculture to being based more on services and manufacturing. The Philippines is a founding member of the United Nations, World Trade Organization, Association of Southeast Asian Nations, the Asia-Pacific Economic Cooperation forum, and the East Asia Summit. The Philippines' position as an island country on the Pacific Ring of Fire and close to the equator makes the country prone to earthquakes and typhoons. The country has a variety of natural resources and a globally significant level of biodiversity.