Benjamin Cowan Shields [Lefty or Big Ben] (June 17, 1903 – January 24, 1982) was a middle relief pitcher in Major League Baseball who played from 1924 through 1931 for the New York Yankees (1924–1925), Boston Red Sox (1930) and Philadelphia Phillies (1931).

In a four-season career, Shields posted 4–0 record with an 8.27 ERA in 13 appearances, including two starts, two complete game, nine strikeouts in 411⁄3 innings pitched.

He holds the major league record for most career wins without a loss (4), despite his high ERA of 8.27.

He benefited from pitching for a powerful Yankees team that featured Babe Ruth and Lou Gehrig among others.

It lowered to 13.50 after the outing that resulted in his fourth win, but only appeared in one major league contest after that.