Juan Sebastián Elcano (Elkano in modern Basque; also known as del Cano; 1486/1487 – 4 August 1526) was a Spanish navigator, ship-owner and explorer best known for having completed the first circumnavigation of the Earth in the ship Victoria on the Magellan expedition to the Spice Islands. He received recognition for his achievement by Charles I of Spain with a coat of arms bearing a globe and the Latin motto Primus circumdedisti me (You were the first to circumnavigate me).

Despite his achievements, information on Elcano is scarce and he is the subject of great historiographical controversy, because of the scarcity of original sources which illuminate his private life and personality. Even in Spain, for example, the first biographies about him were written in the second half of the 19th century, after three centuries of neglect by historians.

Following his success, the king entrusted him with another large expedition to the Spice Islands, headed by the nobleman García Jofre de Loaisa, which was not completed. Elcano died of scurvy in the Pacific Ocean during this venture.

Elcano's name has been written in different ways by historians. His signature seems to read Delcano, or possibly Del Cano, although it is difficult to be sure: Enrique Santamaría shows that his lack of dexterity when signing his name leads him to leave gaps between the letters, so sometimes he signed "del ca no". In Spanish historiography it most commonly has been interpreted as "Del Cano" (or de Cano), but also as simply "Cano".

In the Basque language the form "Elkano" is used. Mitxelena, in his book Apellidos vascos, interprets the surname Elkano from Basque. Between the suffixes -ano and -no, he provides arguments for the latter, the diminutive suffix. He proposes that the first part of the surname is elge. Mitxelena reconstructs the previous form of this elge, and argues that the surname Elkano developed from the association of these two morphemes and that it is also a toponym. It exists in different areas of the Basque Country as a minor place name, but also as the name of a village in Navarre.^{[citation needed]}

Juan Sebastián Elcano's mother was Catalina del Puerto or Catalina Portu, and his father was Domingo Sebastián Elcano. The Portu or Puerto were a powerful family of clergy and scribes. Elcano's grandmother, Catalina's mother, was Domenja Olazabal. Formerly it was believed that she belonged to a noble family of the Tolosa area. It is known that Catalina, who was alive at the time of Elcano's death, asked the king upon her arrival in Getaria 10 years later for the pension that had been promised to Elcano, legally due her according to his will.

Domingo Sebastián Elcano and Catalina Portu had eight children, their first son being born in 1481, and Juan Sebastián being the fourth born son. Next came Domingo Elcano, who was given the name of his father and became a priest in Getaria. The four other sons in the family were Martín Pérez, Antón Martín, Juan Martín, and Ochoa Martín. Martín Pérez, Antón Martín and Ochoa Martín were also mariners, and sailed with Juan Sebastián Elcano in the second expedition to the Moluccas. The daughters, i.e., Juan Sebastián's sisters, were Sebastiana de Elcano and Inés de Elcano. Apparently Elcano also had a half-sister, María, Domingo's illegitimate daughter.

Elcano had two children: a son, Domingo Elcano, with María Hernández de Hernialde in Getaria, and a daughter, María, with a woman called María Bidaurreta in Valladolid. In his will, he bequeathed 100 ducats to his son's mother, María Hernández de Hernialde. To his daughter he left 40 ducats, conditional on her coming to live in Getaria before she was 4 years old.