Born in San Diego, CA, Louis Stephen Marone (December 3, 1945 – November 27, 2015) was a left-handed relief pitcher who appeared in 30 Major League Baseball games as a member of the 1969–1970 Pittsburgh Pirates. He was the cousin of former major league pitcher John D'Acquisto.

Selected by Pittsburgh in the 30th round of the 1965 Major League Baseball draft, Lou was called up to the bigs by the Pirates in May 1969, his fifth professional season, after a strong early season for the Double-A York Pirates. As a Pittsburgh rookie, he appeared in 29 games allowing 24 hits and 13 bases on balls in 34​1⁄3 innings. Of the ten earned runs he allowed in 1969, six came in two rough outings against the St. Louis Cardinals. When he was subsequently sent down, many felt he had earned the right to stay with the club. One final appearance in early 1970, also against the Cardinals, concluded his MLB career.

Stephen's eight-year pro career concluded in minor league baseball, in the Pirates' organization, in 1972.

(excerpted from Baseball Almanac, BR Bullpen & Wikipedia)