Who wrote the book that the film "The Meg" is based upon?

Steve Alten wrote the book that the film The Meg is based upon. The source novel is Meg: A Novel of Deep Terror, published in 1997 and the first book in Alten’s MEG series.

The novel follows Jonas Taylor, a deep-sea pilot and paleontologist who believes that a surviving megalodon—a gigantic prehistoric shark—lurks in the depths of the Mariana Trench. The 2018 film keeps the central idea of an enormous shark but changes many characters, relationships, settings, and plot details, so it is more accurately described as loosely based on the novel.

The movie was directed by Jon Turteltaub and stars Jason Statham as Jonas Taylor. Its screenplay was written by Dean Georgaris, Jon Hoeber, and Erich Hoeber; those writers adapted Alten’s premise for the screen but did not author the original book. That distinction is the most common source of confusion in this question.

The project had a long development history. Disney acquired the film rights in 1996, but several versions stalled before Warner Bros. revived the production. The finished film was released in 2018 and helped bring Alten’s MEG novels to a much wider audience.