Who Is Sylvia?

Who Is Sylvia? may refer to:
 * Who Is Sylvia? (play), a 1950 comedy play by Terence Rattigan
 * Who Is Sylvia? (TV series) a 1967 British television sitcom
 * "Who is Silvia?", song from Shakespeare's play The Two Gentlemen of Verona
 * "Who is Silvia?", English name for Franz Schubert's 1826 German-language Lied "An Sylvia" of Shakespeare's song