April 8 – Hank Aaron hits Home Run number 715, finally breaking Babe Ruth's lifetime Home Run record.
April 14 – Graig Nettles of the New York Yankees hits four home runs during a doubleheader split against his former team, the Cleveland Indians. The Yankees win 9–5, then lose 6–9. Nettles will go on to tie a major league record with 11 home runs in the month of April.
April 26 – The record breaking is not over for Hank Aaron. Today he hits his 15th career grand slam home run, passing Gil Hodges and Willie McCovey for the NL mark. The Braves go on to beat the Cubs, 9-3.
April 30 – At Fenway Park, Nolan Ryan of the Angels strikes out 19 Red Sox batters in a 4-2 victory. In a frightening moment, he hits second baseman Doug Griffin in the head with a fastball. Griffin will be sidelined for two months.
May 1 – Dock Ellis of the Pittsburgh Pirates hits three consecutive batters with pitches in the first inning, setting an ML record, and walks another in the frame before being lifted. Pittsburgh loses 5–3 to the Cincinnati Reds.
Milwaukee third baseman Don Money commits a first-inning error in a 10–5 loss to Minnesota, ending his perfect defensive season after 86 games and 257 chances. He will end the season with just five errors, breaking George Kell's record set in 1950. Money also holds the National League record with just 10 errors, set with the Phillies in 1972, and holds both the National League and American League records for most consecutive chances without an error in a season.
August 20 – Davey Lopes sets a Dodgers record when he totals 15 bases against the Cubs in an 18–8 drubbing at Wrigley Field. Lopes has three home runs, a double and a single in his team's 24-hit attack. The Dodgers totaled 48 bases in the game, a team record.
September 3 – In an amazing performance, SF Giants' John Montefusco makes his major league debut, hits a home run in his first official time at bat off Charlie Hough, and pitches nine innings of relief to earn a 9–5 victory over the Dodgers.
September 11 – The St. Louis Cardinals win a marathon night game against the New York Mets at Shea Stadium, after seven hours four minutes, and 25 innings, the longest game to a decision in major league history. The Cardinals, trailing 3-1 with two out in the ninth, tie the score on Ken Reitz' two-run home run off Jerry Koosman, sending the game into extra innings. Two Mets errors lead to the Cardinals' winning run, starting with an errant pickoff throw that allows Bake McBride to scamper all the way around from first. St. Louis wins, 4–3. The Mets go to the plate 103 times, the only time the century mark has been reached in a major league game; the Cards are not far behind with 99 plate appearances. All told, a record 175 official at-bats are recorded, with a major-league record 45 runners stranded. Only a thousand fans are on hand when the game ends at 3:13 a.m.
September 12 – Tigers pitcher John Hiller picks up his 17th victory in relief, an American League record, as he beats the Brewers, 9–7.
September 25 – Dodgers pitcher Tommy John undergoes surgery to repair the ulnar collateral ligament in his pitching elbow. The surgery, performed by Frank Jobe is now named after the pitcher.
In his last start of the year, Nolan Ryan of the California Angels pitches his third career no-hitter, victimizing the Minnesota Twins, 4–0. In the process, Ryan strikes out 15 batters for the sixth time this season. He also walks eight to run his season total to 202 bases on balls, joining Bob Feller in 1938 as the only pitcher to walk more than 200 in a season. Ryan will set a personal high issuing 204 walks in 1977.
Don Wilson of the Houston Astros throws a 5–0, two-hit shutout against the Braves. It would be Wilson's last major league game, followed barely three months later by his accidental death.
November 20 – Texas Rangers right fielder Jeff Burroughs, who batted .301 with 25 home runs and a league-leading 118 RBI, wins the American League MVP Award. Oakland teammates Joe Rudi, Sal Bando and Reggie Jackson are the runners-up.
December 26 – The Little League is officially opened to girls as President Gerald Ford signs legislation amending the charter of the organization. Little League had sought changes in their charter after a series of lawsuits challenged its boys-only rule.
December 31 – After earning his freedom through arbitration over missed insurance payments by the Oakland Athletics, Jim "Catfish" Hunter is signed to a $3.75 million contract which is slightly more than triple the next highest salary in the game.
January 20 – George Hockette, 72, pitcher for the Boston Red Sox in the mid-1930s.
February 13 – Scrip Lee, 75, Negro league baseball pitcher from 1921 to 1934.
March 1 – Larry Doyle, 87, second baseman, primarily for the New York Giants whom he captained, who batted .300 five times and won the NL's 1912 MVP award; led NL in hits twice and stole home 17 times.
May 5 – Vito Tamulis, 62, left-handed pitcher who posted a 40-28 record with a 3.97 ERA in six seasons for the Yankees, Browns, Dodgers and Phillies.
May 18 – Dan Topping, 61, co-owner and president of the Yankees from 1945 to 1964, during which time the team won ten World Series and fifteen AL pennants.
June 30 – Mule Haas, 70, center fielder for the Athletics and White Sox, who hit two home runs in the 1929 World Series.
July 4 – Del Webb, 75, co-owner and chairman of the Yankees from 1945 to 1964; co-owner Dan Topping had died just weeks earlier.
July 17 – Dizzy Dean, 64, Hall of Fame pitcher who won MVP award in 1934 with 30-7 campaign, the last 30-win season by an NL pitcher; was MVP runnerup the next two years, but an injury in 1937 All-Star game led to end of career; became a broadcaster known for folksy mangling of the English language.
August 8 – Howie Pollet, 53, All-Star pitcher who twice won 20 games for the St. Louis Cardinals.
October 13 – Sam Rice, 84, Hall of Fame right fielder for the Washington Senators who batted .322 lifetime and led AL in steals and triples once each, remembered for disputed catch in 1925 World Series; finished career with 2987 hits, at a time when little attention was paid to career totals.
October 22 – Pat Pieper, 88, the Chicago Cubs field (public address) announcer from 1916 to 1974, a span of 59 years.
October 31 – Buddy Myer, 70, All-Star second baseman for the Washington Senators who batted .303 lifetime and won 1935 batting title.
December 18 – Harry Hooper, 87, Hall of Fame right fielder for the Boston Red Sox and Chicago White Sox, who was an outstanding defensive player and solid leadoff hitter, helping the Red Sox to four champion titles, while retiring with the fifth-most walks in history.