Events in Sport
- May 1 1984 NFL Draft: Irving Fryar from University of Nebraska first pick by New England Patriots
- May 1 NHL Clarence Campbell Conference Final: Edmonton Oilers beat Minnesota North Stars, 4 games to 0
- May 5 110th Kentucky Derby: Laffit Pincay Jr aboard Swale wins in 2:02.4
- May 5 NHL Prince of Wales Conference Final: New York Islanders beat Montreal Canadians, 4 games to 2
Event of Interest
May 6 Baltimore Oriole Cal Ripken Jr hits for cycle

Cal Ripken Jr
- May 7 Sharon Barrett wins LPGA Potamkin Cadillac Golf Classic
Event of Interest
May 8 Minnesota Twins Kirby Puckett debuts with 4 singles

Kirby Puckett
- May 8 USSR announces it will not participate in Los Angeles Summer Olympics
- May 9 Chicago White Sox beat Milwaukee Brewers, 7-6, in 25 innings (started 5/8)
- May 11 Johan Cruijff quits soccer
- May 13 Amy Alcott wins LPGA United Virginia Bank Golf Classic
- May 13 Dutch footballer Johan Cruyff''s last competitive match
- May 16 Juventus of Italy win 24th European Cup Winner's Cup against Porto of Portugal 2-1 in Basel
- May 16 Phillie pitcher Steve Carlton hits a grand slam homer
- May 16 Mackay pays $218,718 for 44,166 tickets to keep Twins in Minnesota Twins sell 51,863 tickets but only 6,346 fans show up for the game
- May 17 Cincinnati Reds Mario Soto throws 4 strikeouts in one inning
- May 19 109th Preakness: Angel Cordero Jr aboard Gate Dancer wins in 1:53.6
- May 19 Stanley Cup: Edmonton Oilers beat NY Islanders, 4 games to 1
Event of Interest
May 19 Pat LaFontaine scores 2 goals within 22 sec in an NHL playoff game

Pat LaFontaine
- May 20 Barb Bunkowsky wins LPGA Chrysler-Plymouth Charity Golf Classic
Event of Interest
May 20 Boston's Roger Clemens beats Twins, 5-4, for his 1st victory

Roger Clemens
- May 23 Detroit Tigers win AL record tying 16th straight road game
- May 24 Det Tigers win AL record 17th straight road game
- May 25 Det Tigers lose to Seattle 7-3 ends record tying 17 consecutive wins
- May 25 Red Sox trade pitcher Dennis Eckersley to Cubs for Bill Buckner
- May 27 Joanne Carner wins LPGA Corning Golf Classic
- May 27 Manuela Manleeva wins 3 singles tennis matches in one day
- May 27 Indianapolis 500: Rick Mears wins in 3:03:21.638 (263.308 km/h)
Event of Interest
May 29 Boston Red Sox retires #9 (Ted Williams) & #4 (Joe Cronin)

Ted Williams
Birthdays in Sport
- May 1 Alexander Farnerud, Swedish footballer
- May 2 Saulius Mikoliūnas, Lithuanian footballer
- May 2 Thabo Sefolosha, American basketball player
- May 4 Manjural Islam, Bangladeshi test cricket player (d. 2007)
- May 4 Kevin Slowey, American baseball player
- May 4 Montell Owens, American football player
- May 7 Alex Smith, American football player
- May 7 Drew Stanton, American football player
- May 7 James Loney, American baseball player
- May 9 Prince Fielder, American MLB player (Milwaukee Brewers), born in Ontario, California
- May 10 Edward Mujica. Venezuelan baseball player
- May 11 Andrés Iniesta Luján, Spanish football player (Barcelona, Spanish national team), born in Fuentealbilla, Spain
- May 14 Michael Rensing, German footballer
- May 14 Nigel Reo-Coker, English footballer
- May 15 Sérgio Jimenez, Brazilian racing driver
- May 16 Jensen Lewis, American baseball player
- May 17 Christian Bolaños, Costa Rican footballer
- May 18 Niki Terpstra, Dutch cyclist
- May 18 Joakim Soria, Mexican baseball player
- May 19 Marcedes Lewis, American football player
- May 24 Brodney Pool, American football player
- May 25 Kyle Brodziak, Canadian ice hockey player
- May 25 Shawne Merriman, American football player
- May 27 Blake Ahearn, NBA basketball player
- May 29 Carmelo Anthony, American basketball player (New York Knicks), born in Brooklyn, New York
- May 30 Jordan Palmer, American football player
- May 31 Nate Robinson, American basketball player