Which explorer completed the first circumnavigation of Earth?

Juan Sebastián Elcano completed the first circumnavigation of Earth.

Elcano commanded the ship Victoria after Ferdinand Magellan died in the Philippines in 1521. The Victoria returned to Sanlúcar de Barrameda, Spain, on 6 September 1522, completing the expedition begun in 1519. Only 18 men returned aboard the Victoria from the original expedition of roughly crew members, and the voyage had lasted nearly three years.

Magellan is often credited with leading the first expedition around the world, but he did not complete the journey himself. Elcano's return voyage across the Indian Ocean and around Africa finished the circuit. The expedition also provided Europeans with practical evidence of the enormous scale of the Pacific Ocean.