- Dec 2 Matteo Darmian, Italian soccer full-back (36 caps; Torino, Manchester United), born in Legnano, Milan, Italy
- Dec 4 Pornanong Phatlum, Thai golfer (British Open 2018 runner-up), born in Khon Kaen, Thailand
- Dec 7 Kyle Hendricks, American MLB pitcher (Chicago Cubs), born in Newport Beach, California
- Dec 8 Drew Doughty, Canadian hockey player, born in London, Canada
- Dec 11 Kellie Harrington, Irish boxer (lightweight Gold Medal 2021 Tokyo Olympics), born in Dublin, Ireland
- Dec 21 Mark Ingram Jr., American football running back (Heisman Trophy 2009, U of Alabama; NFL Pro Bowl 2014, 17, 19; New Orleans Saints, Baltimore Ravens), born in Hackensack, New Jersey
- Dec 29 Kei Nishikori, Japanese tennis player (11 singles titles, only Japanese player ranked in top 10), born in Matsue, Japan
- Dec 30 Ryan Sheckler, American professional skateboarder
About December 1989
How Old? 34 years old
Generation: Millennial
Leap Year: No
Chinese Zodiac: Snake
Star Signs: Sagittarius (Nov 22 - Dec 21), Capricorn (Dec 22 - Jan 19)
Baseball Players
Basketball Stars
Boxers
Footballers
NFL Stars
Tennis Champions