Kluber hurled his third shutout of the season with 12 strikeouts on September 12, 2017, versus the Detroit Tigers, giving the Indians their 20th consecutive win. That tied the 2002 Oakland Athletics for the American League record. Kluber scattered five hits while allowing no walks and struck out eight. He won another AL Player of the Week Award for September 17 after becoming the third Indians pitcher with multiple 250-strikeout seasons. In 22 starts from June 1 through the penultimate, his ERA was 1.62. Named the AL Pitcher of the Month for September, it was Kluber's such third award of the season. His record included a 5−0 W−L, 0.84 ERA, 50 strikeouts and 43 innings pitched. The Indians' record for the month was 25−4, and included the majority of a 22-game win streak that set the American League record, with Kluber helping Cleveland to three of those victories in September. The club won an AL-best 102 games.
In his most dominant season to date, Kluber concluded 2017 leading the major leagues or tying for the lead in each of ERA (2.25), wins (18), complete games (five), shutouts (three),WHIP (0.869), SO/BB (7.36), ERA+ (202), and WAR for pitchers (8.0). He also led the AL in H/9 (6.2) and BB/9 (1.6). His ERA was the lowest for an Indians pitcher to qualify for the ERA title since Gaylord Perry in 1972 (1.92).
Cleveland faced New York in the ALDS, and Kluber started two of the games. He allowed nine runs and four home runs in 6 2⁄3 innings as New York defeated Cleveland in five games. Speculation arose that he had reinjured his back, but Kluber denied such assertions.
End of season awards for Kluber included his second Cy Young Award and selection as a starting pitcher on Baseball America's All-MLB Team.
