The Blue Lagoon is a romance novel written by Henry De Vere Stacpoole and was first published by T. Fisher Unwin in 1908. It is the first novel of the Blue Lagoon trilogy, which also includes The Garden of God (1923) and The Gates of Morning (1925). The novel has inspired several film adaptations, most notably The Blue Lagoon starring Brooke Shields as Emmeline and Christopher Atkins as Richard ("Dicky" in the book), which they are two fictional english children.

The story centers on two cousins, Dicky and Emmeline Lestrange, who are marooned with a galley cook on an island in the South Pacific following a shipwreck. The galley cook, Paddy Button, assumes responsibility for the children and teaches them how to survive, cautioning them to avoid the "arita" berries, which he calls "the never-wake-up berries."

Two-and-a-half years after the shipwreck, Paddy dies following a drinking binge. The children survive on their resourcefulness and the bounty of their remote paradise. They live in a hut and spend their days fishing, swimming, diving for pearls, and exploring the island.

As the years pass, Dicky and Emmeline grow into physically mature young adults and begin to fall in love. Ignorant of their human sexuality, they do not understand or know how to express their physical attraction to one another. Eventually, they consummate their relationship. The author, Henry De Vere Stacpoole, describes their sexual encounter as having been "conducted just as the birds conduct their love affairs. An affair absolutely natural, absolutely blameless, and without sin. It was a marriage according to nature, without feast or guests."