Rex Ellingwood Beach (September 1, 1877 – December 7, 1949) was an American novelist, playwright, and Olympic water polo player.

Rex Beach was born in Atwood, Michigan, but moved to Tampa, Florida, with his family where his father was growing fruit trees. Beach was educated at Rollins College, Florida (1891-6), the Chicago College of Law (1896-7), and Kent College of Law, Chicago (1899-1900). In 1900 he was drawn to Alaska at the time of the Klondike Gold Rush. After five years of unsuccessful prospecting, he turned to writing.