The Lightning Thief is a 2005 American fantasy-adventure novel based on Greek mythology, the first young adult novel by Rick Riordan. The opening installment in the series Percy Jackson & the Olympians, the book was recognized among the year's best for young adults. Riordan followed the novel with various books and spin-off series, spawning the Camp Half-Blood Chronicles media franchise. A film adaptation of the book was released to United States theaters on February 12, 2010. The Disney+ series Percy Jackson and the Olympians adapts The Lightning Thief in its first season, which began December 19, 2023.