Ruy López de Villalobos was a Spanish explorer who led a failed attempt to colonize the Philippines in 1544, attempting to assert Spanish control there under the terms of the treaties of Tordesillas and Zaragoza. Unable to feed his men through barter, raiding, or farming and unable to request resupply from Mexico due to poor knowledge of the Pacific's winds and currents, Villalobos abandoned his mission and fled to the Portuguese-held Moluccas, where he died in prison. He is chiefly remembered for some sources crediting him with naming Leyte the "Philippine Island" in honor of the Spanish crown prince Philip. The name was later extended across the entire Philippine Archipelago and its nation.

There have been several names of the Philippines in different cultures and at different times, usually in reference to specific island groups within the current archipelago. Even the name Philippines itself was originally intended to apply only to Leyte, Samar, and nearby islands. It was bestowed by the Spanish explorer Ruy López de Villalobos or one of his captains Bernardo de la Torre in 1543 in honor of the crown prince Philip, later Philip II. Mindanao, which they reached first and assumed to be the greater land, they named after the reigning emperor Charles V, who was also Spain's king Carlos I. Over the course of Spanish colonization, the name was eventually extended to cover the entire chain. It has survived with minor changes. The Philippine Revolution called its state the Philippine Republic. The US military and civilian occupations called their territory the Philippine Islands. During the Third Philippine Republic, the state's official name was formally changed to the Philippines.