Robert Paul "Tad" Williams is an American fantasy and science fiction writer. He is best known for his multivolume Memory, Sorrow, and Thorn series, the Otherland series, the Shadowmarch series, and The Bobby Dollar series, as well as standalone novels like Tailchaser's Song and The War of the Flowers. Tad has also been involved in the world of comics, having written a six-issue mini-series for DC Comics called The Next, and contributing to titles like Aquaman: Sword of Atlantis.

Williams’s works have sold more than 17 million copies worldwide and have been influential in the fantasy genre. He is currently working on a series titled The Last King of Osten Ard, with its final novel The Navigator's Children scheduled for publication in 2024. In addition, he collaborates with his wife, Deborah Beale, on a young-adult book series called The Ordinary Farm Adventures.

Throughout his life, Williams has been involved in various creative endeavors, including music, radio hosting, and art. He is passionate about writing and remains committed to creating new and imaginative works. He lives in the Santa Cruz mountains with his family.