William J. Juneau (February 24, 1879 – October 9, 1949) was an American football player and coach of football, basketball, and baseball. He served as the head football coach at Colorado College (1904), South Dakota State College of Agricultural and Mechanic Arts (1906–1907), Marquette University (1908–1911), the University of Wisconsin–Madison (1912–1915), the University of Texas at Austin (1917–1919), and the University of Kentucky (1920–1922), compiling a career college football record of 86–39–10. Juneau was also the head basketball coach at South Dakota State for two seasons from 1905 to 1907, tallying a mark of 7–5. He coached baseball at South Dakota State in 1906 and 1908 and at Wisconsin in 1913, amassing a career college baseball record of 15–12–1.