Ralph William Thacker (September 13, 1880 – April 12, 1962) was an American college football and college basketball coach and athletic administrator.

He served as the head football coach at Central Michigan Normal School—now known as Central Michigan University—in 1907, Nebraska State Normal School—now known as Peru State College—from 1911 to 1912, the University of Wyoming from 1913 to 1914, Lake Forest College in 1915, and Macalester College from 1922 to 1924, compiling a career college football head coaching record of 17–33–6.

[1][2] Thacker coached at Traverse City High School in Traverse City, Michigan before he was hired in 1911 at Peru Normal as director of physical training and football coach.

He died on April 12, 1962, in Lincoln, Nebraska, where he had resided for 25 years.

This biographical article relating to a college football coach first appointed in the 1900s is a stub.