Sydney Rosenfeld (1855–1931) was an American playwright who wrote numerous plays, and adapted many foreign plays.
Close to fifty of his creations played on Broadway.
Some of his better known plays (though none achieved long-lasting popularity) included A House of Cards, The King's Carnival, The Lady, or the Tiger?, The Vanderbilt Cup, The Aero Club, The Senator, Mlle.
Mischief, The Mocking Bird, A Man of Ideas, The 20th Century Girl, Jumping Jupiter, and The Optimist.