February 25 – Baseball CommissionerPeter Ueberroth suspends San Diego PadrespitcherLaMarr Hoyt from baseball following his third arrest on drug possession charges, this time on the U.S.-Mexico border. Hoyt is sentenced to 45 days in jail on December 16, 1986. An arbitrator cuts Hoyt's suspension to sixty days in mid-June and orders the Padres to reinstate him. The Padres, however, give him his unconditional release the following day.
March 3 – Ray Dandridge, a third baseman from the Negro Leagues, is the only player elected to the Hall of Fame by the Special Veterans Committee.
April 6 – Al Campanis, a former teammate of Jackie Robinson, appears on the ABC news program, Nightline to discuss the progress of racial integration of baseball on the fortieth anniversary of Robinson's first game. When asked why more African-Americans do not become managers or executives, Campanis states that Blacks lack certain qualities for those jobs, drawing the ire of host Ted Koppel. Campanis is fired as Los Angeles Dodgers general manager two days later.
June 2 – The Seattle Mariners use the number-one overall pick of the draft to select Ken Griffey, Jr., signaling a turnaround in their fortunes as an organization.
June 22 – With their starting rotation decimated by injury, the New York Mets seek help from Tom Seaver, who is not offered a contract to his liking following the 1986 season (his 1986 salary is $1 million; the Boston Red Sox offer him $500,000, which Seaver declines). Though no actual contract is signed, Seaver joins the club on June 6, and is hit hard on in an exhibition game against the Triple-A Tidewater Tides on June 11. After similarly poor outings on the 16th & 20th, he announces his retirement.
September 18 – Darrell Evans hits his 30th home run of the season, and becomes the first player to do so after the age of 40.
September 21 – Darryl Strawberry steals his 30th base of the season to join the 30–30 club. With teammate Howard Johnson already having joined, it marks the first time that two teammates achieve 30-30 seasons in the same year.
October 4 – The Detroit Tigers defeat the Toronto Blue Jays 1-0 to clinch the American League East division title. The victory caps off a thrilling pennant race in which the Tigers overcome a 3.5 game deficit to the Blue Jays in the last two weeks of the season, including sweeping the Blue Jays at Tiger Stadium in the final weekend, and finishing two games ahead of Toronto in the standings.
January 5 – Dale Mitchell, 65, All-Star left fielder and career .312 hitter who spent almost his entire career with the Indians; made the last out in Don Larsen's perfect game in the 1956 World Series, but had only one more major league at bat
January 6 – Margaret Danhauser, 65, outstanding first sacker for the Racine Belles of the All-American Girls Professional Baseball League from 1943 through 1950
January 17 – Ed Busch, 69, shortstop who played from 1943 to 1945 for the Philadelphia Athletics
January 20 – Hank Behrman, 65, pitcher for the Brooklyn Dodgers and New York Giants between 1946 and 1949
November 16 – Jim Brewer, 49, All-Star relief pitcher for the Los Angeles Dodgers who held the club record for career saves
November 17 – Paul Derringer, 81, 6-time All-Star pitcher who had four 20-win seasons for the Cincinnati Reds; earned 2-1 victory in Game 7 of the 1940 World Series
November 21 – Dusty Cooke, 80, outfielder for the New York Yankees, Boston Red Sox and Cincinnati Reds during the 1930s, who later coached and managed with the Philadelphia Phillies
November 27 – Babe Herman, 84, right fielder who batted .324 lifetime, and whose popularity while with the Brooklyn Dodgers was undiminished through a variety of fielding and baserunning lapses; hit for the cycle three times