April 19 – New York Yankees' closer Rich Gossage breaks his right thumb in a clubhouse fight with teammate Cliff Johnson. Gossage would miss almost two months, while 1978 American League Cy Young Award winner Ron Guidry voluntarily replaced him in the bullpen for a short time.
May 9 – With the score tied 4-4 in the ninth inning, and Jimmy Sexton on first base with no outs, the Houston Astros' Terry Puhl lays down a sacrifice bunt. The Cardinals attempt to get the lead runner on the play, however, second base umpire Dave Pallone calls Sexton safe, claiming that Garry Templeton never touched the bag. Cardinals managerKen Boyer, First basemanKeith Hernandez and catcherTed Simmons are ejected from the game. Players on the Cardinals bench begin throwing bats and helmets onto the field in protest. As a result, Pallone orders the entire Cardinals bench into the clubhouse, allowing players only to come onto the field as needed. The Cardinals would get out of the inning without a run scoring, however would lose it in the sixteenth inning.
May 28 – Texas Rangersfirst basemanMike Jorgensen is hit in the head by a pitch from Boston Red SoxpitcherAndy Hassler. Dave Roberts comes into the game to pinch run for Jorgensen, and Pat Putnam takes over as the Rangers' regular first baseman for the next month. Aside from a pinch-hit appearance on May 31, Jorgensen does not play again until July 1. After suffering headaches, it is discovered he has a small blood clot inside his head, which apparently caused a seizure and could have resulted in his early demise.
June 24 – In a 5–1 loss to the Rangers, Rickey Henderson debuts for the Oakland Athletics. He singles and doubles; the first of his over 3,000 career hits, and steals the first of his over 1,400 bases.
July 12 – The Detroit Tigers win the first game of a scheduled doubleheader against the Chicago White Sox, 4–1, on Disco Demolition Night at Chicago's Comiskey Park. Thousands of young fans swarm onto the field between the games, damaging the field and causing mayhem throughout the stadium. The White Sox are forced to forfeit the second game.
July 17 – The National League wins its eighth straight All-Star Game, 7–6, at Seattle. Lee Mazzilli hits a home run to tie the game in the eighth, and walks in the ninth to bring in the winning run. Dave Parker, with two outstanding throws, is named the MVP, and Pete Rose appears in the game playing first base, making him the only player in MLB history to appear in the game at five different positions in the field in his All-Star game career.
September 24 – Pete Rose collects his 200th hit of the season, giving him ten seasons with at least 200 hits. This breaks the record set by Ty Cobb.
September 28 – Garry Templeton of the St. Louis Cardinals collects his 100th hit of the season while batting right-handed. Having already collected 100 hits while batting left-handed, Templeton is the first player in history to accomplish this. He had batted right-handed, exclusively, for the last week of the season to get the needed hits.
October 17 – In Game Seven of the World Series, Willie Stargell hits his third home run of the Series to send the Pittsburgh Pirates to their third straight win over the Baltimore Orioles, to win the World Series Championship. Stargell wins Series MVP honors. The Pirates came back from a deficit of 3 games-to-1.
October 23 – Yankee manager Billy Martin gets into a barroom fight with Joseph Cooper, a marshmallow salesman from Minnesota. Six days later, Martin is fired from the Yankees and replaced with Dick Howser.
November 13 – For the first time ever, there will be League co-MVPs as Keith Hernandez of the St. Louis Cardinals shares the National LeagueBaseball Most Valuable Player Award with Willie Stargell of the Pittsburgh Pirates. Stargell is the oldest person to win this award (since broken by Barry Bonds in 2004). The Pirates have thus won (or shared) all four "Most Valuable Player" awards for the season (All-Star Game, National League Championship Series, World Series, and National League regular season). This is the first such sweep in Major League history (Stargell had won the awards for the NLCS, World Series, and National League regular season, while teammate Dave Parker won the All-Star Game award).
November 20 – California Angels outfielder and DH Don Baylor wins the American League Most Valuable Player Award after hitting .296 with 36 home runs and a major league-leading 120 runs scored and 139 runs batted in. Baylor receives 20 of 28 first-place votes to become the first Angel ever to win MVP honors.
November 26 – Third baseman John Castino, who batted .285 for the Minnesota Twins, and shortstop Alfredo Griffin, who hit .287 for the Toronto Blue Jays, tie for the American League Rookie of the Year Award, each receiving seven of the 28 first-place votes. The deadlock precipitates a change in the voting system, effective in 1980.
July 12 – Tom Lovelace, 81, pinch hit in one game with the Pittsburgh Pirates in 1922.
July 22 – Amos Strunk, 90, a center fielder for the Philadelphia Athletics, Boston Red Sox and Chicago White Sox between 1908 and 1924 and a member of four World Series champion teams
August 2 – Thurman Munson, 32, 7-time All-Star catcher for the New York Yankees since 1969 who batted .300 five times and won the 1976 MVP award; 1970 Rookie of the Year won three Gold Gloves and batted .357 in 30 postseason games
August 9 – Walter O'Malley, 75, owner of the Dodgers franchise since 1950, during which time the team won four World Series titles; he moved the team from Brooklyn to Los Angeles and constructed Dodger Stadium
September 4 – Turkey Stearnes, 78, center fielder in the Negro Leagues who led the Negro National League in home runs six times while batting .350
October 22 – John Drebinger, 88, sportswriter for The New York Times for 41 years
November 18 – Freddie Fitzsimmons, 78, knuckleball pitcher who won 217 games for the New York Giants and Brooklyn Dodgers
December 4 – Bert Delmas, 68, infielder for the 1933 Brooklyn Dodgers
December 15 – Stan Hack, 70, 5-time All-Star third baseman for the Chicago Cubs who batted .301 lifetime and posted a .394 career on-base percentage, the highest of any 20th-century third baseman; scored 100 runs seven times and led NL in hits and steals twice each