Nicknamed "Red" for the color of his hair, Dunn possessed an equally colorful personality. He earned five letters competing in football, basketball and baseball at Marquette Academy. Dunn later attended Marquette University, earning All-America honors while leading the Golden Avalanche in 1922 and 1923 to a 17–0–1 record. While a Packer, he served as Curly Lambeau's "field general" for the 1929, 1930, and 1931 NFL Champions.