Pebble in the Sky is a science fiction novel by American writer Isaac Asimov, published in 1950. This work is his first novel — parts of the Foundation series had appeared from 1942 onwards in magazines, but Foundation was not published in book form until 1951. The original Foundation books are also a string of linked episodes, whereas this is a complete story involving a single group of characters.

Isaac Asimov was an American writer and professor of biochemistry at Boston University. During his lifetime, Asimov was considered one of the "Big Three" science fiction writers, along with Robert A. Heinlein and Arthur C. Clarke. A prolific writer, he wrote or edited more than 500 books. He also wrote an estimated 90,000 letters and postcards. Best known for his hard science fiction, Asimov also wrote mysteries and fantasy, as well as popular science and other non-fiction.