March 20 – In a special election held by the Baseball Writers' Association of America, the late Roberto Clemente receives 393 of 424 votes to earn entry into the Hall of Fame. The Hall's Board of Directors had earlier waived the five-year-wait rule for Clemente.
June 23 – Pitcher Ken Brett of the Philadelphia Phillies tops the Montreal Expos 7–2, and hits a home run for his fourth consecutive game, setting a major league record. Previously, Brett hit home runs on June 9, 13, and 18. He will total 10 for his career.
July 3 – Brothers Gaylord Perry (Indians) and Jim Perry (Tigers) pitch against each other for the only time in their careers. Neither finishes the game, but Gaylord is charged with the 5–4 loss. Two Norm Cash home runs help the Tigers.
July 9 – In a record-setting walkathon between the Cincinnati Reds and Montreal Expos, 25 bases on balls are handed out as Montreal strolls to an 11–6 win. Well off the American League's two-team mark of 30, this tops the National League record of 23, last reached on July 7, 1911. Six Montreal pitchers walk 16, one short of the record for an NL team, while two Reds pitchers walk nine. Hal King pinch hits a grand slam for the Reds in the 6th inning, his second pinch homer in nine days.
August 6 – An exhibition game between the Milwaukee Brewers and the Atlanta Braves held at Milwaukee draws 33,337. The Brewers win, 7–5, in the fourth and last exhibition between the two teams. But the big thrill is provided by Hank Aaron, who hits a home run.
August 11 – Chicago White Sox rookie Brian Downing cracks his first major league hit, a home run off Detroit's Mickey Lolich. Downing's debut dinger is a first in the majors since at least 1945 – an inside-the-park homer. It'll be matched in two years by the Giants Johnnie LeMaster, who will do it in his first at bat.
September 3 – The San Francisco Giants overcome a 7 – 1 deficit to beat the Los Angeles Dodgers 11 – 8 at Candlestick Park during a nationally televised Monday Night baseball game on NBC. Bobby Bonds hit a walk-off grand slam into the right field seats to win the game for the Giants.
September 7 – Whitey Herzog is fired by the Texas Rangers with the club in the American League West cellar at 47-91. Del Wilber serves as interim manager for one game before owner Bob Short names Billy Martin, fired by the Tigers earlier in the season, as Herzog's permanent replacement.
October 1 – Two make-up games were played after the scheduled end of the regular season on September 30: the Mets won at the Cubs 6–4 and the Pirates lost at home to the Padres 3–4, a possible second game between the Cubs and Mets was not necessary anymore.
October 14 – In one of the more bizarre games in World Series history, the Mets defeat the Athletics 10-7 in 12 innings in Game 2 by scoring four runs in the 12th, three of which were the result of two errors by Oakland second baseman Mike Andrews. After the game, Athletics owner Charlie O. Finley forced Andrews to sign a false affidavit stating he was disabled, which would have rendered him ineligible for the remainder of the series. A's manager Dick Williams rallied to Andrews' defense and commissioner Bowie Kuhn nullified the affidavit. Nevertheless, Finley ordered Williams to bench Andrews for the remainder of the series. Williams, in defiance, sent Andrews to the plate as a pinch hitter in Game 4 in New York three nights later as the Mets' home crowd gave a standing ovation.
October 23 – Athletics owner Charlie Finley reveals that he will not release manager Dick Williams from his contract unless he receives adequate compensation from the team that signs him. Williams had resigned following the World Series victory two days earlier.
January 9 – Lyn Lary, 66, shortstop for seven teams who led AL in steals in 1936
February 28 – Syl Simon, 75, infielder and pinch hitter for the Browns who played in the minor leagues after losing much of his left hand in an accident
March 12 – Frankie Frisch, 74, Hall of Fame second baseman for the Giants and Cardinals who scored 100 runs seven times, led the NL in steals three times, and was the 1931 MVP; a lifetime .316 hitter, he twice batted .400 in the World Series, and also managed the Cardinals to the 1934 World Series title
March 26 – George Sisler, 80, Hall of Fame first baseman for the St. Louis Browns widely recognized as the best defensive player ever at that position, he twice batted over .400 and hit .340 lifetime; the AL's 1922 MVP, he had a record 257 hits in 1920 and also led the league in steals four times
April 13 – Clarence Blethen, 79, pitcher for the Boston Red Sox and Brooklyn Dodgers between 1923 and 1929
May 19 – Jim Moore, 69, pitcher who played from 1928 to 1932 for the Cleveland Indians and Chicago White Sox
June 11 – Bill Burwell, 78, pitcher for the St. Louis Browns in 1920–21, later a scout
June 23 – Cliff Aberson, 51, two-sport athlete who was a left fielder for the Chicago Cubs from 1947 to 1949, and a halfback with Green Bay Packers in 1945
July 2 – Chick Hafey, 70, Hall of Fame left fielder for the St. Louis Cardinals and Cincinnati Reds, a career .316 hitter who made the first hit in All-Star history and was the first batting champion to wear eyeglasses
July 2 – George McBride, 92, shortstop for the Washington Senators known for his defense
July 7 – Paul Musser, 84, pitcher for the Washington Senators (1912) and Boston Red Sox (1919)
July 12 – Billy Urbanski, 70, shortstop for the Boston Braves from 1931 to 1936
August 7 – Wilbur Cooper, 81, pitcher who won over 200 games for the Pittsburgh Pirates, he was the first NL left-hander to reach that milestone