The Once and Future King is a collection of fantasy novels by T. H. White about the legend of King Arthur. It is loosely based upon the 1485 work Le Morte d'Arthur by Sir Thomas Malory. It was first published in 1958 as a collection of shorter novels that were published from 1938 to 1940, with some new or amended material. The title refers to a legend that Arthur will one day return as king.

Terence Hanbury "Tim" White was an English writer. He is best known for his Arthurian novels, which were published together in 1958 as The Once and Future King. One of his most memorable is the first of the series, The Sword in the Stone, which was published as a stand-alone book in 1938.