Warren Kendall Lewis (21 August 1882 – 9 March 1975) was an MIT professor who has been called the father of modern chemical engineering.[1] He co-authored an early major textbook on the subject[2] which essentially introduced the concept of unit operations. He also co-developed the Houdry process under contract to The Standard Oil Company of New Jersey (now ExxonMobil) into modern fluid catalytic cracking with Edwin R. Gilliland, another MIT professor.