John Robert Kline (January 27, 1929 – October 26, 2021) was an American professional baseball player.

A shortstop, his 12-year career included one season in Major League Baseball as a member of the 1955 Washington Senators.

Kline threw and batted right-handed and was listed as 6 feet (1.8 m) tall and 179 pounds (81 kg).

[1] In 1954 he was the All-Star shortstop of the Double-A Southern Association, and at the end of that season he was selected by Washington in the Rule 5 draft.

He was the starting shortstop for the home side in the annual Presidential Opener at Griffith Stadium on April 11, 1955; he was hitless in two at-bats against Lou Kretlow of the Baltimore Orioles and left the game for a pinch hitter in the sixth inning.