The name is borne by Don Juan, a character from Spanish legend who, after killing his lover's father, is dragged to hell by the father's ghost. The story was adapted into plays by Tirso de Molina (1630) and Molière (1665), an opera by Mozart (1787), and an epic poem by Byron (1824), among other works.
The French theologian Jean Calvin (1509-1564) and the philosophers Jean-Jacques Rousseau (1712-1778) and Jean-Paul Sartre (1905-1980) are well-known bearers of this name. It was also borne by the German-French Dadaist artist Jean Arp (1886-1966).
Other famous bearers of this name include Spanish painter Diego Velázquez (1599-1660), Mexican muralist Diego Rivera (1886-1957) and Argentine soccer player Diego Maradona (1960-2020).
Other notable bearers of the name include the Russian emperor Boris Godunov (1552-1605), later the subject of a play of that name by Aleksandr Pushkin, as well as the Russian author Boris Pasternak (1890-1960), the Bulgarian king Boris III (1894-1943), and the Russian president Boris Yeltsin (1931-2007).
As an English name it can also derive from the month of August, which was named for the Roman emperor Augustus.