Pauline Baynes (born September 9, 1922 , in Hove, Sussex) is an English book illustrator, whose work encompasses more than 100 books, notably those by C. S. Lewis and J. R. R. Tolkien.

Though her early years were spent in India, where her father was commissioner in Agra, she and her elder sister came to England for their schooling. Baynes attended the Slade School of Fine Art, but after a year she volunteered to work for the Ministry of Defence, where she made demonstration models for instruction courses. This work did not last long as she was soon transferred to a map-making department (knowledge of which she later employed to good effect when she drew maps of Narnia for C. S. Lewis and of Middle-earth for J. R. R. Tolkien).

Baynes is probably best known for her illustrations in The Chronicles of Narnia by C. S. Lewis. She was also J. R. R. Tolkien's chosen illustrator: Farmer Giles of Ham, The Adventures of Tom Bombadil, Smith of Wootton Major, Tree and Leaf, and after Tolkien's death the poem Bilbo's Last Song (as a poster in 1974, as a book in 1990). She also painted the covers for the British 1973 one-volume and 1981 three-volume paperback editions of The Lord of the Rings, and produced illustrated versions of the maps from The Lord of the Rings and The Hobbit.