João Rodrigues Serrão, also known as Juan Rodríguez Serrano, was a Portuguese and Spanish pilot and explorer. He served in the Portuguese India Armadas that secured control of the Indian Ocean and the Strait of Malacca for the Portuguese but is most well known for his participation in Ferdinand Magellan's 1519–1521 expedition to the Spice Islands for Charles I of Spain, which discovered a path around South America to the Pacific and initiated Spanish involvement in the Philippines. Serrão and Duarte Barbosa became leaders of the expedition after Magellan's death at the Battle of Mactan but did not live to complete the circumnavigation with Elcano. They were both killed shortly thereafter during a massacre of the Spanish by their supposed convert and ally Humabon, raja of Cebu.

The Magellan expedition, also known as the Magellan-Elcano expedition, was a 16th-century Spanish expedition planned and led by Portuguese explorer Ferdinand Magellan. One of the most important voyages in the Age of Discovery—and in the history of exploration—its purpose was to cross the Atlantic and Pacific Oceans to open a trade route with the Moluccas, or Spice Islands, in present-day Indonesia. The expedition departed Spain in 1519 and returned there in 1522 led by Spanish navigator Juan Sebastián Elcano, who crossed the Indian Ocean after Magellan's death in the Philippines. Totaling 60,440 km, or 37,560 mi, the nearly three-year voyage achieved the first circumnavigation of Earth in history. It also revealed the vast scale of the Pacific Ocean and proved that ships could sail around the world on a western sea route.