On June 15, 1938, Johnny Vander Meer of the Cincinnati Reds became the only pitcher in major league history to pitch two consecutive no-hitters. Four days earlier, the left-handed Vander Meer held the Braves hitless at Crosley Field, leading the Reds to a 3-0 victory. Then, on June 15th, he defeated the Dodgers at Brooklyn’s Ebbets Field, 6-0.
Vander Meer in 1948 (Baseball Digest)