Ronald Frank Mrozinski (September 16, 1930 – October 19, 2005) was an American professional baseball player, a pitcher who played in 37 Major League Baseball games over two seasons, 1954 and 1955, for the Philadelphia Phillies. His professional career spanned fourteen years, from 1949 until 1962. Born in White Haven, Pennsylvania, he threw left-handed, batted right-handed, and was listed as 5 feet 11 inches (1.80 m) tall and 160 pounds (73 kg). Ron Mrozinski died at his home in Washington, New Jersey.