January 5 – Boston Red Sox pitcher Tim Wakefield escapes serious injury when he is hit by a car while out jogging. He is released from the hospital after being treated for bruises.
January 6 – Knuckleballer Phil Niekro is elected to the Hall of Fame by the Baseball Writers' Association of America. Niekro receives 80.34% of the vote. Pitcher Don Sutton falls nine votes short of election.
April 15 – In an unprecedented move, Commissioner of BaseballBud Selig announces on the 50th Anniversary of Jackie Robinson's debut that the number he wore with the Brooklyn Dodgers, number 42, would be unilaterally retired throughout all of Major League Baseball during a mid-game ceremony in a game between the Dodgers and the New York Mets at Shea Stadium Rachael Robinson, Jackie's widow and President Bill Clinton attend the event as well. The number would be worn by players during the anniversary of his major league debut, and would still be worn by players who started wearing the number before the announcement, most famously the New York Yankees' Mariano Rivera, until he retired after the 2013 season, thus officially retiring number 42, as he was the last player to wear the number 42 jersey on a regular basis.
May 7 – The Montréal Expos score a National League-record 13 runs in the 6th inning of their game against the San Francisco Giants on the way to a 19–3 win. The Expos send 17 batters to the plate. Mike Lansing homers twice in the inning to drive in five runs, becoming the third Expos player to perform the feat, and the first NL second baseman to do so since Bobby Lowe in 1894.
May 8 – At home, the Baltimore Orioles stop Randy Johnson's 16-game win streak with a decisive 13–3 pasting of the Seattle Mariners. Baltimore is led by catcher Chris Hoiles, who collects six RBI on two homers and a double. Johnson strikes out 10 in six innings, but gives up five runs on six hits and two walks in his attempt to become the first AL pitcher since Dave McNally (1968–69) to win 17 straight.
May 27 – Barry Larkin's streak of consecutively reaching base 13 times is stopped by Curt Schilling, who goes all the way to beat Cincinnati 2–1. Larkin singles in the first inning, but flies out in the 3rd to end his streak one shy of Pedro Guerrero's NL record, set in 1985.
May 30 – The Orioles' Mike Mussina retires the first 25 Indian batters before Sandy Alomar, Jr. ruins his no-hit bid with a one-out single in the 9th. Mussina then strikes out the final two batters for a 3–0 victory.
May 31 – Cal Ripken, Jr. snaps a 7th-inning tie with a record-breaking home run as the Baltimore Orioles rally from a 4-run deficit to beat the Cleveland Indians 8–5. Ripken's homer gives him 4,274 total bases with Baltimore, breaking the franchise mark for total bases in a career. Baltimore also place Eric Davis on the disabled list. Davis is suffering from colon cancer and will be operated on in early June.
May 31 – In Miami, Andrés Galarraga golfs a 529-foot grand slam, the longest home run ever at Pro Player Stadium. His homer gives the Colorado Rockies a 7–0 lead over the Florida Marlins, and they eventually win 8–4. Galarraga has three home runs in the past three games against Florida that traveled 1,435 feet, an average of 478 feet. He hit a 455-foot homer two days before and a 451-foot homer the previous day. The longest previous homer at the stadium was 482 feet by Pete Incaviglia of the Phillies off Al Leiter on May 1, 1996.
July 12 – At a sold out Three Rivers Stadium, Francisco Córdova pitched nine innings of a combined 10-inning no-hitter for the Pittsburgh Pirates. Ricardo Rincón pitched the 10th inning. The Pirates won the game on a dramatic three run, pinch hit home run in the bottom of the 10th by Mark Smith.
September 10 – Mark McGwire joins Babe Ruth as the only players in major league history with 50 home runs in consecutive seasons by hitting a 446-foot shot off Shawn Estes in the third inning of the St. Louis Cardinals' road game against the San Francisco Giants. McGwire, who hit a major league-leading 52 homers for the Oakland Athletics last season, becomes the first player with back-to-back 50-homer seasons since Ruth did it in 1927 and 1928.
January 6 – Dick Donovan, 69, All-Star pitcher, mainly with the White Sox and Indians, who led AL in ERA in 1961 and won 20 games in 1962
January 20 – Curt Flood, 59, All-Star center fielder who won seven Gold Gloves and batted .300 six times; challenged baseball's reserve clause all the way to the U.S. Supreme Court, unsuccessfully, after refusing a trade
February 7 – Manny Salvo, 83, Boston pitcher who tied for the National League lead in shutouts in 1940
February 13 – Bobby Adams, 75, third baseman for the Cincinnati Reds/Redlegs, Chicago White Sox, Baltimore Orioles and Chicago Cubs between 1946 and 1959
June 1 – Mickey Rocco, 81, Cleveland first baseman who led the American League in fielding percentage at his position in 1943 and 1945
June 9 – Thornton Lee, 90, All-Star pitcher who won over 100 games for the White Sox; won 22 games and led AL in ERA in 1941
July 31 – Eddie Miller, 80, 7-time All-Star shortstop for four NL teams who led league in fielding five times
August 23 – Guy Curtright, 84, White Sox outfielder who finished sixth in 1943 American League batting race with a .291 average
September 9 – Richie Ashburn, 70, Hall of Fame center fielder for the Phillies who batted .308 lifetime, winning two batting titles, and led NL in putouts nine times, hits three times, triples twice and steals once; retired with six of the top eight single-season putout totals in history
September 22 – Eddie Sawyer, 87, manager who led the Phillies' "Whiz Kids" to the 1950 pennant, later a scout
September 26 – Woody English, 91, All-Star infielder for the Cubs who batted .300 twice
October 6 – Johnny Vander Meer, 82, All-Star pitcher for the Cincinnati Reds who in 1938 became the only player to pitch two consecutive no-hitters; led NL in strikeouts three times
October 21 – Dolph Camilli, 90, All-Star first baseman who was the NL's MVP in 1941, leading the Brooklyn Dodgers to the pennant; had five 100-RBI seasons
November 2 – Roy McMillan, 68, All-Star shortstop for the Reds, Braves and Mets who won the NL's first three Gold Gloves; minor league manager, coach and scout
November 20 – Dick Littlefield, 71, well-traveled pitcher who played for nine teams, earning 15 of his 33 wins with the Pirates
November 27 – Buck Leonard, 90, Hall of Fame first baseman of the Negro Leagues regularly among the league leaders in batting average and home runs