Robert Paul "Tad" Williams is an American fantasy and science fiction writer. He is the author of the multivolume Memory, Sorrow, and Thorn series, Otherland series, Shadowmarch series, and The Bobby Dollar series, as well as the standalone novels Tailchaser's Song and The War of the Flowers. Most recently, Williams published The Last King of Osten Ard series, with its final novel The Navigator's Children being published in 2024. More than 17 million copies of Williams' works have been sold.