Champions
Major League Baseball
World Series: Cincinnati Reds over Detroit Tigers (4-3) All-Star Game, July 9 at Sportsman's Park: National League, 4-0
Other champions
Amateur World Series: Cuba
Negro League Baseball All-Star Game: East, 11-0
Awards and honors
Most Valuable Player
Hank Greenberg (AL) – OF, Detroit Tigers
Frank McCormick (NL) – 1B, Cincinnati Reds
The Sporting News Player of the Year Award
Bob Feller – P, Cleveland Indians
The Sporting News Most Valuable Player Award
Hank Greenberg (AL) – OF, Detroit Tigers
Frank McCormick (NL) – 1B, Cincinnati Reds
The Sporting News Manager of the Year Award
Bill McKechnie – Cincinnati Reds
Statistical leaders
Major league baseball final standings
American League final standings
National League final standings
Negro league baseball final standings
Negro American League final standings
Negro National League final standings
Events
January
January 1 - Kenesaw Mountain Landis voids a trade that would have sent pitcher George Coffman and second baseman Benny McCoy to the Philadelphia A's in exchange for outfielder Wally Moses. Landis claims the Tigers hid McCoy as his reason for voiding the trade, setting in motion a decision he would make later that month. January 10- The Brooklyn Dodgers signed pitcher Wes Ferrell as a free agent. January 14 – Commissioner Kenesaw Mountain Landis declares 87 players from the Detroit Tigers' farm system free agents because they had been "hidden" from other teams. The move allows Benny McCoy to sign with the Philadelphia A's as a free agent. January 31 - Catcher and future spy for the U.S. Government, catcher Moe Berg, is released by the Boston Red Sox.
February
February 2 - The election of a Negro National League president ends in a deadlock, with three owners voting for incumbent Tom Wilson and three voting for New York City businessman C. B. Powell. February 23 - A compromise by Alex Pompez ended a three-week stalemate between the Negro National League clubs over the election of a league president and the role of promoter Eddie Gottlieb. League president Tom Wilson, vice president Ed Bolden, and secretary Cumberland Posey were all reelected for the 1940 season. Newark Eagles owner Abe Manley, who opposed Wilson's reelection, became league treasurer. Gottlieb was allowed to continue promoting the majority of games at Yankee Stadium, but the New York Black Yankees were allowed to promote a double-header at their own home field. February 24 - The Brooklyn Dodgers work out a trade with the Boston Red Sox. The deal sees the Dodgers Send Red Evans and Art Parker, along with $3,500 cash to acquire Pee Wee Reese.
March
March 7 - The National League defeats the AL in a charity exhibition All-Star game. The contest is broadcast on the Mutual Broadcasting System raises more than $20,000. The funds are used to help citizens of Finland whose homes and businesses were destroyed in an attack by the USSR.
April
April 16 – The Cleveland Indians' Bob Feller pitches a 1-0 opening day no-hitter against the Chicago White Sox. April 23 – Hall of famer Pee Wee Reese makes his major league debut at shortstop for the Brooklyn Dodgers. April 30 – Tex Carleton pitches a no-hitter as the Brooklyn Dodgers defeat the Cincinnati Reds, 3–0.
May
May 7 -The St. Louis Cardinals defeat the Brooklyn Dodgers, 18–2. The Cards have 49 bases on twenty hits, including thirteen extra-base hits and seven home runs. May 8 - The Cincinnati Reds trade outfielder Vince DiMaggio to the Pittsburgh Pirates for outfielder Johnny Rizzo. May 13 - Pitcher Willis Hudlin is released by the Cleveland Indians. Three days later he signs with the Washington Senators and continues a journey that will see him pitch for four different teams in the 1940 season. May 20 - Pinky Higgins belts three home runs, hitting them in the fourth, fifth, and seventh innings in the Tigers 10–7 win over Boston. May 22 - The Brooklyn Dodgers sign Al Campanis as a free agent. May 24 - The St. Louis Browns play their first home game under artificial lights, but the hometown fans go home unhappy as the team falls to Bob Feller and the Cleveland Indians 3–2. In the National League on the same night, the New York Giants defeat the Boston Braves 8–1 in the first night game played at the polo grounds.