Robert P. Knowles (February 25, 1916-November 3, 1985) was a Wisconsin politician. Born in River Falls, Wisconsin, Knowles graduated from the University of Wisconsin–River Falls. Knowles served in the Wisconsin State Senate from 1955 until 1975; his older brother was Warren P. Knowles, Governor of Wisconsin.[1][2] Knowles was defeated for re election in 1976 by Democrat Michele Radosevich 52%-48%.