Thornton Oakley (March 27, 1881 – April 4, 1953) was an American artist and illustrator.
Thornton Oakley was born on Sunday, March 27, 1881, in Pittsburgh. He was the son of John Milton Oakley and Imogen Brashear Oakley. He graduated from Shady Side Academy in 1897, and studied at the University of Pennsylvania, receiving B.S. and M.S. degrees in architecture in 1901 and 1902.
Oakley began his study of illustration with Howard Pyle in 1902, working both at Pyle's winter studio on North Franklin St. in Wilmington, Delaware, and at his summer studio in Chadds Ford, Pennsylvania, which was situated in the old mill that now houses the Brandywine River Museum. He described his first day with Pyle in a talk given in 1951 at the Free Library of Philadelphia:
"There we four - my new cronies - Allen Tupper True, George Harding, Gordon McCouch and I - made our first sketches from a model, and our efforts were frightful to behold! Not one of us had had a palette in our hands ever before: I had not the least idea as to procedure. My attempts were terrifying to behold, and when H.P. came to me to criticize my work he paused for a long, long time before speaking, and I know that he must have been appalled."