Guillermo "Memo" Luna Romero (born June 25, 1930 in Mexico City) is a retired Mexican professional baseball player, a left-handed pitcher whose career extended from 1949 through 1961 and who pitched one game of Major League Baseball for the 1954 St. Louis Cardinals. He stood 6 feet (1.8 m) tall and weighed 168 pounds (76 kg).Luna had two outstanding seasons in the minor leagues.