John Griffith London (born John Griffith Chaney; January 12, 1876 – November 22, 1916) was an American novelist, journalist, and social activist. A pioneer in the world of commercial magazine fiction, he was one of the first writers to become a worldwide celebrity and earn a large fortune from writing. He was also an innovator in the genre that would later become known as science fiction.

His most famous works include The Call of the Wild and White Fang, both set in the Klondike Gold Rush, as well as the short stories "To Build a Fire", "An Odyssey of the North", and "Love of Life". He also wrote about the South Pacific in stories such as "The Pearls of Parlay" and "The Heathen".

London was part of the radical literary group "The Crowd" in San Francisco and a passionate advocate of unionization, socialism, and the rights of workers. He wrote several powerful works dealing with these topics, such as his dystopian novel The Iron Heel, his non-fiction exposé The People of the Abyss, and The War of the Classes.