- May 1 Alexander Farnerud, Swedish soccer midfielder (8 caps; Strasbourg, Young Boys), born in Landskrona, Sweden
- May 1 David Backes, American ice hockey center (NHL All Star 2011; Olympic silver 2010; St. Louis Blues, Boston Bruins), born in Minneapolis, Minnesota
- May 1 Mišo Brečko, Slovenian soccer defender (77 caps; FC Köln, FC Nürnberg), born in Trbovlje, Slovenia
- May 2 Saulius Mikoliūnas, Lithuanian footballer, born in Vilnius, Lithuanian SSR
- May 2 Thabo Sefolosha, Swiss basketball player, born in Vevey, Switzerland
- May 4 Manjural Islam Rana, Bangladeshi cricket all-rounder (6 Tests, 1 x 50, 5 wickets, BB 3/84; Khulna Division), born in Khulna, Bangladesh (d. 2007)
- May 4 Montell Owens, American football fullback (Pro Bowl 2010, 11 Jacksonville Jaguars), born in Wilmington, Delaware
- 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 baseball first baseman (6 x MLB All Star, NL HR leader 2007, MLB RBI leader 2009, 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 15 Sérgio Jimenez, Brazilian racing driver
- May 16 Darío Cvitanich, Argentine football player, born in Baradero, Argentina
- May 16 Rick Rypien, Canadian ice hockey player, born in Alberta, Canada (d. 2011)
- May 16 Tomáš Fleischmann, Czech ice hockey player, born in Kopřivnice, Czechoslovakia
- May 17 Christian Bolaños, Costa Rican footballer, born in Hatillo, Costa Rica
- May 18 Joakim Soria, Mexican baseball pitcher (MLB All Star 2008, 10; Kansas City Royals), born in Monclova, Mexico
- May 18 Niki Terpstra, Dutch cyclist, born in Beverwijk, Netherlands
- May 18 Simon Pagenaud, French auto racer (IndyCar champion 2016; Indianapolis 500 2019), born in Poitiers, France
- May 19 Marcedes Lewis, American NFL tight end (Pro Bowl 2010; Jacksonville Jaguars, Green Bay Packers), born in Los Alamitos, California
- May 21 Brandon Fields, American football punter (Second-team All-Pro & Pro Bowl 2013; Miami Dolphins), born in Southfield, Michigan
- May 21 Gary Woodland, American golfer (US Open 2019), born in Topeka, Kansas
- May 24 Brodney Pool, American football player (Cleveland Browns), born in Corpus Christi, Texas
- May 25 Kyle Brodziak, Canadian ice hockey player, born in St. Paul, Alberta, Canada
- May 25 Shawne Merriman, American football player, born in Washington, D.C.
- May 29 Carmelo Anthony, American basketball forward (10-time NBA All Star), born in Brooklyn, New York
- May 30 Jordan Palmer, American football player
- May 31 Nate Robinson, American basketball player (first three-time slam dunk champion), born in Seattle, Washington
About May 1984
How Old? 39 years old
Generation: Millennial
Leap Year: Yes
Baseball Players
Basketball Stars
Boxers
Footballers
NFL Stars
Tennis Champions