Sidney is an English surname with two possible origins: the Norman place name Saint-Denis, or the Old English for "wide island" or "wide meadow". The Elizabethan poet Sir Philip Sidney made it an aristocratic first name, and the actor Sidney Poitier gave it dignity in 20th-century America. Sidney stood at number 595 in 2000, fell out of the boys' top 1000 after 2014 and ranks number 1327 in 2025.