Richard Russell Riordan Jr. ( RY-ər-dən; born June 5, 1964) is an American author, best known for writing the Percy Jackson & the Olympians series. Riordan's books have been translated into forty-two languages and sold more than thirty million copies in the United States. 20th Century Fox adapted the first two books of his Percy Jackson series as part of a series of films in which Riordan was not involved. Riordan currently serves as a co-creator and executive producer on the television series adaption of the book series that was released on Disney+ in 2023. Riordan's books have also spawned other related media, such as graphic novels and short story collections. Riordan's first full-length novel was Big Red Tequila, which became the first book in the Tres Navarre series. His big breakthrough was The Lightning Thief (2005), the first novel in the five-volume Percy Jackson and the Olympians series, which placed a group of modern-day adolescents in a Greco-Roman mythological setting. Since then, Riordan has written The Heroes of Olympus, a sequel to the Percy Jackson series; The Kane Chronicles, a trilogy of similar premise focusing on Egyptian mythology; and Magnus Chase and the Gods of Asgard, again a trilogy of similar premise focusing on Norse mythology. Riordan also helped Scholastic Press develop The 39 Clues series and its spinoffs, and penned its first book, The Maze of Bones. In 2021, he published Daughter of the Deep. His third standalone novel, The Sun and the Star, co-written with author Mark Oshiro, was published on May 2, 2023.