Beyond Thirty is a short science fiction novel by American writer Edgar Rice Burroughs. It was written in 1915 and first published in All Around Magazine in February 1916, but did not appear in book form in Burroughs' lifetime. The first book edition was issued by Lloyd Arthur Eshbach's Fantasy Press fanzine in 1955; it then appeared in the collection Beyond Thirty and The Man-Eater, published by Science-Fiction & Fantasy Publications in 1957.

Edgar Rice Burroughs (1875-1950) was an American novelist, best known for his creation of the iconic characters Tarzan and John Carter. His writing career began in earnest with the publication of 'A Princess of Mars' in 1912 and he soon became a seminal figure in the development of science fiction and fantasy genres. Burroughs's literary style combined vivid imagination with swift-paced adventure narratives that often featured lost civilizations, otherworldly spectacles, and a distinctive exploration of the heroic ideal. 'Beyond Thirty', also known as 'The Lost Continent', is one of his notable works that exemplify Burroughs's penchant for speculative imagination. This novel, penned during the turbulent times of World War I, presented a dystopian vision of a future where Western Civilization has collapsed, and a brave American navigates the strange cultures that have risen in Europe's ruins. It reflects Burroughs's fascination with the themes of civilization's fragility and mankind's resilience. His prolific output includes over 70 books, and his work has been translated into countless languages, ensuring his place as a cornerstone in the pantheon of American literature. Burroughs's influence can still be seen in contemporary literature and media, underpinning the enduring popularity of the escapist adventure genre.