April 12 – The first official game at the Astrodome is played in front of over 43,000 fans, as they watch the Philadelphia Phillies defeat the host Astros, 2-0.
April 28 – Lindsey Nelson, broadcaster for the New York Mets, calls today's Mets-Astros game from a gondola suspended above second base in the Astrodome.
June 8 – The first Major League draft is held for high school and collegiate players. The Kansas City Athletics use the first overall pick to draft Rick Monday. In the tenth round, the New York Mets pick up Nolan Ryan.
July 3 – The Minnesota Twins defeat the Kansas City Athletics 3-2. Coupled with a Cleveland Indians loss, the Twins move into a tie for first place. They gain sole possession of first place on July 5, and are in first by four games by the time they complete a nine-game winning streak on July 10. They do not relinquish their lead for the remainder of the season.
July 13 – At Minnesota's Metropolitan Stadium, Willie Mays hits a home run with two walks and two runs to pace the National League to a 6–5 All-Star Game victory over the American League. Juan Marichal pitches three scoreless innings to earn Game MVP.
August 22 – During a game between the Los Angeles Dodgers and San Francisco Giants at Candlestick Park, San Francisco's starting pitcher, Juan Marichal, batting against Sandy Koufax in the third inning, attacks Dodgers catcherJohn Roseboro with his bat. Both benches clear and a 14-minute brawl ensues, before peacemakers such as Koufax and the Giants' Willie Mays restore order. A shaken-up Koufax then gives up a 3 run homer to Mays and the Giants win 4-3 to retake first place. National League president Warren Giles suspends Marichal for eight games and fines him $1,750, and also forbids him to travel with his team to Dodger Stadium for the final series of the season against the Dodgers.
August 26 - Tug McGraw allows 2 runs in 7.2 innings and the Mets beat the Dodgers and Sandy Koufax 5-2. It is the first time in 14 career games that the Mets beat the future Hall-of-Famer. Koufax have been 13-0 against the Mets until this game.
August 30 – Casey Stengel announces his retirement as manager of the New York Mets, ending a fifty-five-year career as player and manager. He is the only person to have played for or managed all four of New York's Major League clubs.
September–December
September 2 – Ernie Banks hits his 400th career home run helping the Chicago Cubs beat the St. Louis Cardinals 5-3. Also on September, in preparation of their move the following season to Anaheim, the Los Angeles Angels change their name to the California Angels.
September 8 – Against the California Angels at Municipal Stadium, Bert Campaneris of the Kansas City Athletics becomes the first player to play all nine positions in the same game, as part of a special promotion featuring the popular young player. He begins the game at shortstop and plays, in order for the next eight innings, second base, third base, left field, center field, right field, first base, pitcher and catcher. With the game tied at 3-3 after nine innings, Rene Lachemann replaces Campaneris, who was injured in a collision at the plate with Ed Kirkpatrick to end the top of the ninth. California scores two runs in the 13th inning and defeats Kansas City 5-3.
September 9 – At Dodger Stadium, a duel between the Los Angeles Dodgers' Sandy Koufax and Bob Hendley of the Chicago Cubs is perfect until Dodger left fielder Lou Johnson walks in the fifth inning. Following a sacrifice bunt, Johnson steals third base and scores on a throwing error by Cubs catcher Chris Krug. Johnson later has the game's only hit, a 7th-inning double. Koufax's fourth no-hitter in four years is a perfect game, the first in Dodgers history. One hit by two clubs in a completed nine-inning game is also a major league record, as is the one runner left on base. The two base runners in a game is an ML record. For Chicago pitchers, it is the second one-hitter they've thrown against the Dodgers this year and lost. A week later in the rematch in Chicago's Wrigley Field, Hendley beats Koufax and the Dodgers, 2-1. The Cubs won't be no-hit again until July 25,, by Philadelphia Phillie Cole Hamels—a span of 7,920 games.
September 13 – The San Francisco Giants' Willie Mays' hits his 500th home run off the Houston Astros' Don Nottebart, and Juan Marichal earned his 22nd victory as the Giants beat Houston 5-1 at the Astrodome. The win is the Giants' 11th straight and gives them a two and a half game lead.
September 16 – Before only 1,247 fans at Fenway Park, Dave Morehead of the Boston Red Soxno-hits the Cleveland Indians 2-0, on the same day the Red Sox fire Pinky Higgins as general manager. Not until Hideo Nomo in will another Red Sox pitcher hurl a no-hitter, and the next Fenway Park no-hitter won't come until . The lone Indian baserunner comes on Rocky Colavito's second-inning walk. The home plate umpire is Ed Runge, whose grandson Brian would call balls and strikes for Jonathan Sánchez's no-hitter.
September 18 – "Mickey Mantle Day" is celebrated at Yankee Stadium on the occasion of Mantle's 2,000th career game.
September 22 – The Milwaukee Braves play their final game in Milwaukee, losing to the Los Angeles Dodgers 7-6 in 11 innings.
September 25
*Though he has not pitched in the Major Leagues since, the Kansas City Athletics send Satchel Paige to the mound. At 59 years old, he is the oldest pitcher in Major League history. In three innings, he strikes out one, and gives up one hit, a single to Carl Yastrzemski. Paige does not earn a decision in the loss to Boston, 5-2.
*Mudcat Grant, pitching for the Minnesota Twins, wins his 20th game, becoming the first black 20-game winner in the American League. Next month, he'll be the first black winner of a World Series game, and only the seventh pitcher to homer in one.
September 26
*The Minnesota Twins gain their first American League pennant since moving from Washington in 1961 by defeating the expansion Washington Senators 2-1 at Washington, D.C. Stadium. Minnesota's Jim Kaat wins the clincher.
*Don Drysdale holds the St. Louis Cardinals to five hits, and the Los Angeles Dodgers win their ninth in a row to move back into a tie for first place. The streak reaches thirteen.
October 2
*Sandy Koufax wins his 26th game as the Dodgers beat the Braves 2-1, for their 14th win in their last 15 games as they clinch the N.L. pennant.
*The New York Mets and Philadelphia Phillies play to a 0-0 tie after eighteen innings.
October 7 – Jim Kaat gives Minnesota a 2-0 World Series lead by driving in two runs, defeating Sandy Koufax and the Los Angeles Dodgers 5-1 at Minnesota's Metropolitan Stadium. The game is remembered for Minnesota's Bob Allison making a remarkable sliding catch of a Jim Lefebvre line drive in the wet grass of Metropolitan Stadium.
October 14 – Working on two days rest, Sandy Koufax strikes out ten and throws a three-hit, 2–0 shutout against the Minnesota Twins in Game Seven of the World Series, giving the Los Angeles Dodgers a second World Championship in three years. Lou Johnson's fourth inning leadoff home run off the left field foul pole gives Koufax the only run he'll need. A Ron Fairly double and Wes Parker single in the same inning add an insurance run to account for the 2-0 final. Koufax, who threw complete game shutouts in games 5 and 7, is named Series MVP.
October 19 – The Houston Astros trade catcher Jerry Grote to the New York Mets for a player to be named later and cash. On November 24, The Mets sent Tom Parsons to the Astros to complete the trade.
November 10 – San Francisco Giants outfielder Willie Mays, who hit.312 with 52 home runs and 112 RBI, is named National League MVP. Mays receives 224 votes to 177 for Sandy Koufax, who pitching for the Los Angeles Dodgers posted a 26-8 record with a 2.04 ERA and 382 strikeouts, allowing just 5.79 hits per nine innings.
November 26 – Los Angeles Dodgers second baseman Jim Lefebvre, who hit.250 with 12 home runs and 69 RBI, is voted National League Rookie of the Year over Houston Astros second baseman Joe Morgan and San Francisco Giants pitcher Frank Linzy.
December 9 – Frank Robinson is traded by the Cincinnati Reds to the Baltimore Orioles for pitcher Milt Pappas, outfielder Dick Simpson, and pitcher Jack Baldschun; Robinson will win the triple crown and the MVP Award in the American League next year, leading the Orioles to the World Series title.
March 5 – Pepper Martin, 61, four-time All-Star third baseman/outfielder and an integral member of the St. Louis Cardinals' legendary Gashouse Gang of the 1930s, who batted.298 over a 13-year career, led the National League with 122 runs scored in 1933, also in stolen bases three times, and was the catalyst in a Cardinals' upset victory over the Philadelphia Athletics in the 1931 World Series.
March 5 – Tadashi Wakabayashi, 57, Hall of Fame Japanese Baseball and NPB pitcher who played for the Osaka/Hanshin Tigers and the Mainichi Orions from 1936 to 1953.
March 6 – Wally Schang, 75, American League catcher for 19 seasons, including three world champions.
March 9 – Frank Graham, 71, New York sportswriter for over 50 years.
April
May
May 13 – Dick Wantz, 25, California Angels pitcher, following surgery for brain cancer, who had made his debut only one month earlier, pitching one inning of relief in his only major league appearance.
May 23 – Earl Webb, 67, outfielder for 7 seasons, who hit an MLB single season record 67 doubles for the Red Sox in 1931.
May 29 – Mike McNally, 72, infielder for the Boston Red Sox, New York Yankees and Washington Senators from 1915 to 1925, and later a minor league manager and scout during almost two decades.
July 15 – Harry Fanwell, 78, pitcher for the 1910 Cleveland Naps.
August
August 21 – Bill Harris, 65, pitcher for the Reds, Pirates and Red Sox, who also tossed two no-hitters in the International League with the 1936 Buffalo Bisons.
August 25 – Moonlight Graham, 87, outfielder for the New York Giants in 1905 whose story was popularized in the novel Shoeless Joe and the film Field of Dreams.
August 29 – Paul Waner, 62, Hall of Fame right fielder who won three batting titles and the National League's 1927 MVP award with the Pittsburgh Pirates, becoming the seventh player to make 3,000 hits.
September
September 22 – Biz Mackey, 68, five-time All-Star catcher and manager of the Negro Leagues.
October 29 – Frank Fuller, 72, second baseman for the Detroit Tigers and Boston Red Sox.
October 29 – Bill McKechnie, 79, Hall of Fame manager who became the first person to lead three different teams to pennants: the Pirates, Cardinals, and Reds, winning the World Series in 1925 and 1940.
December 9 – Branch Rickey, 83, executive who revolutionized the game first by establishing the farm system of player development, and again by signing Jackie Robinson to integrate the major leagues.
December 9 – Dutch Sterrett, 76, pitcher for the New York Yankees from 1912 to 1913.
December 19 – John Knight, 80, shortstop who spent 24 years in baseball, including major league stints with the Philadelphia Athletics, Boston Americans, New York Highlanders/Yankees and Washington Senators.