From late 1944 onwards, an American attack on the Philippines became probable. The Japanese High Command realized that if the Americans reoccupied the Philippines, then the sea routes between the resource-rich southern portions of their empire and the home islands would be severed. The American air force from the Philippines would prevent any Japanese merchantsfrom sailing in the South China Sea. Then, Japan would not be able to obtain rubber, tin, oil and other essential raw materials from the southern part of their empire and its war economy would collapse. So the Philippines had to be defended at any cost. Most of the literature dealing with the American ‘liberation’ of the Philippines from the Japanese focuses on the naval battles in the Leyte Gulf rather than on the ground fighting in the islands of the Philippine Archipelago. This chapter discusses both the naval operations and the ground battle. The first section discusses the planning behind the Philippines Operation. The next section deals with air-naval encounters which made the ground battle in the Philippines possible.