Sir Thomas Malory (c.1399 – March 14, 1471) was the author or compiler of Le Morte d'Arthur. The antiquary John Leland believed him to be Welsh, but most modern scholarship and this article assumes that he was Sir Thomas Malory of Newbold Revel in Warwickshire. The surname appears in various spellings, including Maillorie, Mallory, "Mallery", and Maleore. The name comes from the Old French adjective maleure (from Latin male auguratus) meaning ill-omened or unfortunate.

Few facts are certain in Malory's history. He was probably born sometime around 1405 (though some scholars have suggested an earlier date). He died in March of 1471, less than two years after completing his great book. Twice elected to a seat in Parliament, he also accrued an impressive list of criminal charges during the 1450s, which included burglary, rape, sheep stealing, and attempting to ambush the Duke of Buckingham. He escaped from jail on two occasions, once fighting his way out using a variety of weapons and swimming a moat. He was imprisoned at several locations in London, but was occasionally out on bail. He was never brought to trial for the charges that had been levelled against him. In the 1460s he was at least once pardoned by the king (Henry VI), but more often, he was specifically excluded from pardon by both Henry VI and his rival and successor, Edward IV. It is clear, from comments Malory makes at the ends of sections of his narrative, that he composed at least part of his work while in prison. His description of himself in the colophon to Le Morte d'Arthur has led to speculation that he may have been a priest, though this is not widely considered: [1]

I pray you all, gentlemen and gentlewomen that readeth this book of Arthur and his knights, from the beginning to the ending, pray for me while I am alive, that God send me good deliverance, and when I am dead, I pray you all pray for my soul. For this book was ended the ninth year of the reign of King Edward the Fourth, by Sir Thomas Maleore, knight, as Jesu help him for His great might, as he is the servant of Jesu both day and night.
A young Malory appears as a character at the end of T.H. White's book The Once and Future King, which was based on Le Morte d'Arthur; this cameo is included in the Broadway musical Camelot. Many modern takes on the Arthurian legend have their roots in Malory, including John Boorman's 1981 movie Excalibur, which included all the elements of the book.