A famous bearer was the 14th-century Jewish philosopher Abner of Burgos, called Alfonso of Valladolid after he converted to Christianity. It has been used as an English Christian given name since the Protestant Reformation. It was popular with the Puritans, who brought it to America in the 17th century.
Famous bearers of the name include the English poet Edmund Spenser (1552-1599), the German-Czech philosopher Edmund Husserl (1859-1938) and New Zealand mountaineer Edmund Hillary (1919-2008), the first person to climb Mount Everest.
As a given name, it has traditionally been more masculine than feminine. In America however, after the variant Sydney became popular for girls, Sidney was used more for girls than boys between 1993 and 2019.