William J. Rennie

William J. "Big Bill" Rennie (September 12, 1891 – December 10, 1964) was an American football, basketball, and baseball coach and athletics administrator. Rennie served as the head football coach at Hillsdale College in Hillsdale, Michigan from 1920 and 1921, compiling a record of 11–4–1. Rennie was also the head basketball coach at Hillsdale from 1920 to 1922, tallying a mark of 12–16.

Rennie was born on September 12, 1891, in Holly, Michigan, to William and Marian Deller Rennie. He played college football at Hillsdale College as a tackle and center, and was elected captain of the 1914 team. Rennie also played basketball and baseball at Hillsdale before graduating in 1915. He then taught English and pursued graduate work at the University of Washington.

Rennie served as an officer in the United States Army during World War I. On the recommendation of Illinois's athletic director, George Huff, Rennie was hired that fall as football coach by Central High School in Muskogee, Oklahoma. In, 1923, Rennie was offered the head coaching position at James Millikin University—now known as Millikin University—in Decatur, Illinois.

On August 12, 1920, Rennie married Elizabeth Adelaide Goodrich in Hillsdale. The two were both members of the Hillsdale College's class of 1915. Rennie was later regarded as an expert in fly fishing. He died on December 10, 1964, at the Hillsdale Community Health Center, following a long illness.