Ronald Parker Mills (born February 25, 1951) is an American former competition swimmer and Olympic medalist.
Mills competed at the age of 17 at the 1968 Summer Olympics in Mexico City. He swam the backstroke leg for the gold medal-winning U.S. team in the preliminary heats of the men's 4×100-meter medley relay. Individually, he received a bronze medal for his third-place finish in the men's 100-meter backstroke.
After the Olympics, he attended Southern Methodist University in Dallas, Texas, where he swam for the SMU Mustangs swimming and diving team in National Collegiate Athletic Association (NCAA) competition. He went on to earn All-American honors and was the Southwest Conference champion in eight individual swimming events over a three-year span. He also swam on an American record-setting relay team, and was later inducted into the Texas Swimming & Diving Hall of Fame.