John Guille Millais (24 March 1865 – 24 March 1931) was a British artist, naturalist, ornithologist, gardener and travel writer who specialized in wildlife and flower portraiture.
Millais travelled extensively around the world in the late Victorian period detailing wildlife often for the first time. He is noted for illustrations that are of a particularly exact nature. .
He was a son of the artist Sir John Everett Millais and his wife Euphemia Gray.