Samuel Wilson Parr (January 21, 1857 – May 16, 1931) was an American chemist and academic from Illinois. A graduate of the Illinois Industrial University (University of Illinois at Urbana–Champaign), he taught at Illinois College after receiving a master's degree from Cornell University. He was recruited by the University of Illinois in 1891 and remained there for the rest of his career. Parr is noted for his contributions to industrial chemistry, including the identification of the alloy illium, named for the school. In 1928, Parr was the president of the American Chemical Society.