John Ernst Steinbeck Jr. (; February 27, 1902 – December 20, 1968) was an American writer and the 1962 Nobel Prize in Literature winner "for his realistic and imaginative writings, combining as they do sympathetic humor and keen social perception". He has been called "a giant of American letters."

During his writing career, he authored 33 books, with one book coauthored alongside Edward Ricketts, including 16 novels, six non-fiction books, and two collections of short stories. He is widely known for the comic novels Tortilla Flat (1935) and Cannery Row (1945), the multi-generation epic East of Eden (1952), and the novellas The Red Pony (1933) and Of Mice and Men (1937). The Pulitzer Prize–winning The Grapes of Wrath (1939) is considered Steinbeck's masterpiece and part of the American literary canon. In the first 75 years after it was published, it sold 14 million copies.

Most of Steinbeck's work is set in central California, particularly in the Salinas Valley and the California Coast Ranges region. His works frequently explored the themes of fate and injustice, especially as applied to downtrodden or everyman protagonists.