March 3 – Ray Dandridge, a third baseman from the Negro Leagues, is the only player elected to the Hall of Fame by the Special Veterans Committee.
April 6 – Los Angeles DodgersGeneral managerAl Campanis, a former teammate of Jackie Robinson, appears on the ABC news program, Nightline to discuss the progress of racial integration of baseball on the fortieth anniversary of Robinson's first game. When asked why more African-Americans have not become managers or executives, Campanis states that Blacks may lack certain qualities for those jobs, drawing the ire of host Ted Koppel. Campanis was fired two days later.
June 2 – The Seattle Mariners use the number-one overall pick of the draft to select Ken Griffey, Jr., signaling a turnaround in their fortunes as an organization.
July 14 – Tim Raines caps a 3-for-3 performance in the All-Star Game with a two-run triple in the top of the 13th inning, giving the National League a 2–0 victory over the American League. Raines is selected the MVP.
July 18 – New York Yankees first baseman Don Mattingly homers in his record-tying eighth straight game, in a 7–2 loss to the Texas Rangers. He ties the record set by Dale Long in 1956.
August 11 – Mark McGwire of the Oakland Athletics breaks Al Rosen's American League rookie record by hitting his 38th home run in an 8–2 loss to the Mariners.
August 30 – With knuckleball pitcher Charlie Hough on the mound, Texas Rangers catcher Geno Petralli ties a Major League record by committing six passed balls in a 7–0 loss to the Detroit Tigers at Tiger Stadium. All seven runs are unearned and come as a result of the passed balls. Petralli will go on to commit 35 passed balls on the season, breaking J. C. Martin's single-season record of 33 in 1965.
September 9 – Nolan Ryan strikes out 16 to pass 4,500 for his career as the Houston Astros beat the San Francisco Giants 4–2. Ryan strikes out 12 of the final 13 batters and fans Mike Aldrete to complete the seventh inning for his 4,500th strikeout.
September 18 – Darrell Evans hits his 30th home run of the season, and becomes the first player to do so after the age of 40.
September 21 – Darryl Strawberry swipes his 30th base of the season to join the 30–30 club. With teammate Howard Johnson already having joined, it marks the first time that two teammates achieve 30–30 seasons in the same year.
October 4 – The Detroit Tigers defeat the Toronto Blue Jays 1–0 to clinch the American League East division title. The victory caps off a thrilling pennant race in which the Tigers overcame a 3.5 game deficit to the Blue Jays in the last two weeks of the season, including sweeping the Blue Jays at Tiger Stadium in the final weekend, and finishing two games ahead of Toronto in the standings.
October 25 – In Game Seven of the World Series, starter Frank Viola and reliever Jeff Reardon hold the St. Louis Cardinals to six hits, as the Minnesota Twins win 4–2 for their second World Championship, and their first since moving to Minnesota and changing their name to the Twins. The franchise's first title came in 1924 as the Washington Senators. Viola is named the Series MVP.
