1990 in baseball
Champions
Major League Baseball
- World Series: Cincinnati Reds over Oakland Athletics ; José Rijo, MVP
- American League Championship Series MVP Dave Stewart
- National League Championship Series co-MVPs: Rob Dibble and Randy Myers
- All-Star Game, July 10 at Wrigley Field: American League, 2–0; Julio Franco, MVP
Other champions
- Baseball World Cup: Cuba
- Caribbean World Series: Leones del Escogido
- College World Series: Georgia
- Japan Series: Seibu Lions defeated the Yomiuri Giants
- Korean Series: LG Twins over Samsung Lions
- Big League World Series: Taipei, Taiwan
- Junior League World Series: Yabucoa, Puerto Rico
- Little League World Series: San-Hua, Tainan County, Taiwan
- Senior League World Series: Taipei, Taiwan
- Taiwan Series: Wei Chuan Dragons defeated the Mercuries Tigers
Awards and honors
- Baseball Hall of Fame
- *Joe Morgan
- *Jim Palmer
- Most Valuable Player
- *Rickey Henderson, Oakland Athletics
- *Barry Bonds, Pittsburgh Pirates
- Cy Young Award
- *Bob Welch, Oakland Athletics
- *Doug Drabek, Pittsburgh Pirates
- Rookie of the Year
- *Sandy Alomar Jr., Cleveland Indians
- *David Justice, Atlanta Braves
- Manager of the Year Award
- *Jeff Torborg, Chicago White Sox
- *Jim Leyland, Pittsburgh Pirates
- Woman Executive of the Year : Leanne Pagliai, Riverside Red Wave, California League
- Gold Glove Award
- *Mark McGwire
- *Harold Reynolds
- *Kelly Gruber
- *Ozzie Guillén
- *Ellis Burks
- *Ken Griffey Jr.
- *Gary Pettis
- *Sandy Alomar Jr.
- *Mike Boddicker
- *Andrés Galarraga
- *Ryne Sandberg
- *Tim Wallach
- *Ozzie Smith
- *Barry Bonds
- *Tony Gwynn
- *Andy Van Slyke
- *Benito Santiago
- *Greg Maddux
MLB statistical leaders
Major League Baseball final standings
;American League;National League
Managers
American League
National League
Events
January
- January 2 – The Chicago Cubs release Vance Law.
- January 9:
- *Jim Palmer, a three-time American League Cy Young Award winner, and Joe Morgan, a two-time National League MVP, are elected to the Hall of Fame by the Baseball Writers' Association of America in their first year of eligibility.
- *The Major League Baseball Players Association sends a letter to all clubs advising them that spring camps will not be opened.
- January 15 – The Detroit Tigers sign Cecil Fielder as a free agent. Fielder returns to the states after playing the previous season for the Hanshin Tigers of the Japan Central League.
- January 19 – After being released by the New York Mets, Gary Carter signs a free agent contract with the San Francisco Giants.
- January 28 – Dan Quisenberry is signed as a free agent by the San Francisco Giants.
February
- February 15:
- *A thirty-two-day lockout begins as Major League Baseball owners refuse to open spring training camp without reaching a new Basic Agreement with the players. The regular season is delayed one week due to the lockout.
- *After spending the previous seasons with the California Angels and Kansas City Royals, Bill Buckner returns to the Boston Red Sox as a free agent. A combination of injuries and fans that wouldn't forgive him for his error that ultimately cost the Red Sox the 1986 World Series send Buckner into retirement mid way through the season.
- February 17 – The New York Yankees sign free agent pitcher Mariano Rivera.
March
- March 19 – MLB commissioner Fay Vincent announces a new four-year agreement between 1990 and 1993. The agreement may be reopened by either the players association or teams owners after three years, as well as the minimum salary is raised to $100,000 from $68,000. Besides, the pension/benefit plan contribution by the owners increases to an average of $55 million over the four years while the salary arbitration eligibility stays at three years, but the top 17% of two-year players by service time are also now eligible as free agents. Better known as Super Two, this eligibility represents about 15 players per year.
- March 26 – Hoping to duplicate the success the New York Yankees had with Deion Sanders, the New York Mets sign Minnesota Vikings running back D.J. Dozier, who was also looking to become a two sport star. The Dozier experiment fails as he only plays 25 games at the major league level.
April
- April 3 – The Chicago White Sox release pitcher Jerry Reuss. Reuss would sign two weeks later with the Houston Astros.
- April 9 – Glenn Davis of the Houston Astros reaches base three times after he's hit by a pitch. Davis is plucked by Reds pitchers Randy Myers, Rob Dibble, and Norm Charlton. Interaction with a Houston sports writer after the game Myers replies, "We're Nasty Guys", was led to the Reds trio of relievers being called "The Nasty Boys".
- April 10 – U.S. President George H. W. Bush throws out the first pitch at a game in Toronto, making him the first U.S. President to toss the first pitch in a foreign country.
- April 11 – At Anaheim Stadium, California Angels pitchers Mark Langston and Mike Witt combine to no-hit the Seattle Mariners, 1–0, for the first combined no-hitter in the major leagues since 1976. It is Langston's first start for the Angels since signing as a free agent in the off-season. Angels first baseman Wally Joyner makes an error in the fifth inning when he overthrows Langston on Pete O'Brien's grounder. O'Brien tries for second base‚ not realizing that catcher Lance Parrish backs up the play, and he is out.
- April 14 – CBS officially assumes the role as Major League Baseball's network broadcast partner with coverage of the Chicago Cubs at Pittsburgh and Los Angeles at Houston.
- * For the first time in MLB history, two Cy Young Award winners contribute to the victory. Bret Saberhagen, gets the win, while the reigning CY Young Award winner, relief pitcher Mark Davis, picks up the save in the Royals win over the Toronto Blue Jays.
- April 20:
- *Pete Rose pleads guilty to two charges of filing false income tax returns not showing income he receives from selling autographs, memorabilia, and from horse racing winnings.
- *After retiring the first 26 Oakland Athletics batters, Brian Holman loses a perfect game when Ken Phelps hits a home run in an eventual 6–1 Seattle Mariners win.
- April 23 – During an in-season exhibition game against the cross-town rival Chicago Cubs, Steve Lyons of the Chicago White Sox plays all nine positions during the game. However, because it is an exhibition, Lyons is not officially credited with the feat.
- April 26 – Nolan Ryan pitches a one-hitter and sets a Texas Rangers record with 16 strikeouts in a 1–0 win over the Chicago White Sox. It is also the 12th career one-hitter for Ryan, which ties him with Major League Baseball leader Bob Feller, as well as his 200th career game with at least 10 strikeouts. Ron Kittle of the White Sox had the only hit for Chicago, a single.
- April 27 – The Milwaukee Brewers release first baseman Terry Francona.
- April 29 – Opting to not be placed on the disabled list, Dan Quisenberry announces his retirement. He only appeared in five games for the Giants.
- April 30 – In a game between the New York Mets and Atlanta Braves, Braves hitter Mark Lemke hits a ball that is fielded by Mets infielder Gregg Jeffries, who then tosses the ball to Mets pitcher David Cone. Lemke is ruled safe by first base umpire Charlie Williams. Cone has a meltdown on the field, and begins to argue with Williams, thus allowing two Braves runners to score in the process.
May
- May 4 – The Boston Red Sox trade relief pitcher Lee Smith to the St. Louis Cardinals in exchange for outfielder Tom Brunansky.
- May 5 – The St. Louis Cardinals sign free agent Terry Francona.
- May 11 – The California Angels trade pitcher Mike Witt to the New York Yankees in exchange for outfielder Dave Winfield.
- May 22 – Andre Dawson of the Chicago Cubs is intentionally walked by Cincinnati Reds' pitching five times, becoming the first player to do so in Major League Baseball history.
- May 26 – The Philadelphia Phillies retire eventual Baseball Hall of Famer Mike Schmidt's number 20.
- May 29 – Oakland Athletics outfielder Rickey Henderson steals third base in the sixth inning of a game versus the Toronto Blue Jays. The steal allows Henderson to pass Ty Cobb for most bases stolen in American League history.
June
- June 2 – At the Kingdome, Randy Johnson of the Seattle Mariners no-hits the Detroit Tigers 2-0. The no-hitter is the first in both Mariner and Kingdome history.
- June 6 – The highest-profile managerial firing of 1990 season happens when the New York Yankees fire Bucky Dent before a game against their rivals at Fenway Park, where he hit his famous three-run home run in a one-game playoff game in, making Fenway Park the scene of his greatest moment as a player and worst moment as manager. Prior to the game, Yankees broadcaster Tony Kubek blasts owner George Steinbrenner before a television audience, saying the firing of Dent was "mishandled" and calling Steinbrenner a "loser", "bully", and a "coward".
- June 11 – Nolan Ryan pitches the sixth no hitter of his career by defeating the Oakland Athletics in Oakland, 5-0.
- June 12 – The Pittsburgh Pirates' Sid Bream and Kansas City Royals' Bill Pecota each went 4-for-4, but neither one scored or drove in a run.
- June 14 – It is announced that the National League expands by two teams for the 1993 season.
- June 22 – The Atlanta Braves fire manager Russ Nixon and replace him with general manager Bobby Cox.
- June 29 – For the first time in major league history, two no-hitters are thrown on the same day in both leagues. Dave Stewart for the Oakland Athletics, no-hits his future team, the Toronto Blue Jays, at SkyDome. Hours later, Dodger pitcher Fernando Valenzuela no-hit the St. Louis Cardinals at Dodger Stadium.