Sir William Rothenstein (29 January 1872 – 14 February 1945) was an English painter, printmaker, draughtsman and writer on art. He is best known for his work as a war artist in both World Wars and as a portrait artist. More than 200 of his portraits of famous people are in the National Portrait Gallery collection. He co-founded the Carfax Gallery that held exhibitions of works of the Camden Town Group. Rothenstein was a Principal at the Royal College of Art from 1920 to 1935 and was knighted in 1931.