Steven Jack Kline (born October 6, 1947 in Wenatchee, Washington) is a retired American professional baseball player, a former starting pitcher who appeared in Major League Baseball from 1970 through and in 1977. Listed at tall and , Kline batted and threw right-handed.
Kline was 22 years old when he reached the majors in 1970 with the New York Yankees, spending four and a half years with them before moving to the Cleveland Indians (1974) and Atlanta Braves (1977). In his rookie season for the Yankees he went 6-6 with a 3.41 ERA in 15 starts, and won 12 games a year later, including career-numbers with 81 strikeouts and 15 complete games.
His most productive season came in 1972, when he recorded career-highs in wins (16), ERA (2.40), starts (32), shutouts (4), and innings pitched (236 ). He declined after that and was sent to Cleveland in a major early season 1974 trade that sent Chris Chambliss and Dick Tidrow to the Bronx. Kline missed the 1975 season with arm problems, and spent 1976 back in minor league baseball before making 16 relief appearances for Atlanta in 1977, his last Major League season.
In a six-season MLB career, Kline posted a 43-45 record with 240 strikeouts and a 3.26 ERA in 750 innings and 129 games pitched, 105 as a starter. He allowed 708 hits and 184 bases on balls.