- Jan 4 Victor Wembanyama, French basketball player (San Antonio Spurs), born in Le Chesnay, France
- Jan 15 Grace VanderWaal, American singer-songwriter (America's Got Talent, 2016 - "I Don't Know My Name"), born in Lenexa, Kansas
- Jan 21 Princess Ingrid Alexandra of Norway
- Feb 6 Princess Louise of Belgium, born in Woluwe-Saint-Lambert, Belgium
Millie Bobby Brown (20 years old)
Feb 19 English actress (Stranger Things) and UNICEF goodwill ambassador, born in Marbella, Spain
- Mar 12 DannyLux, Mexican-American singer-songwriter (Jugaste Y Sufri), born in Palm Springs, California
- Mar 13 Coco Gauff, American tennis player (US Open 2023), born in Delray Beach, Florida
- Mar 20 Yunchan Lim, South Korean pianist (youngest winner, at 18, Van Cliburn International Piano Competition), born in Siheung, South Korea
- Mar 21 Count Claus-Casimir of Orange-Nassau, Jonkheer van Amsberg
- Mar 27 Amira Willighagen, Dutch classical cross-over soprano singer (Holland's Got Talent, 2013), born in Nijmegen, Netherlands
Charli D'Amelio (20 years old)
May 1 American dancer considered TikTok's biggest star, born in Norwalk, Connecticut
- May 10 The Gosselin Sextuplets
Peyton Elizabeth Lee (20 years old)
May 22 American actress (Andi Mack; Doogie Kameāloha, M.D.), born in New York City
- Jun 8 EmiSunshine [Emilie Sunshine Hamilton], American country-folk singer-songwriter, guitarist and ukulele player, born in Madisonville, Tennessee
- Jun 10 Gayle [Taylor Gayle Rutherfurd], American singer-songwriter (ABCDEFU), born in Plano, Texas
- Jun 19 Millie Gibson, English actress know for Doctor Who, born in Tameside, Greater Manchester
- Jul 26 Dilano van 't Hoff, Dutch racingcar driver (F4 Spanish Championship, 2021), born in Dordrecht, Netherlands (d. 2023)
- Aug 4 Savanna Shaw, American pop singer (Mat and Savanna), born in Utah
- Aug 14 Marsai Martin, American actress and producer (Black-ish), born in Plano, Texas
- Aug 19 Siena Agudong, American actress (No Good Nick), born in Kauai, Hawaii
- Aug 31 Jang Won-young, South Korean pop singer (Ive; Iz*One), born in Seoul, South Korea
- Sep 1 Iam Tongi, American singer (American Idol season 21 winner), born in Kahuku, Hawaii
- Oct 3 Noah Schnapp, American actor (Stranger Things), born in New York City
- Nov 16 Jack Champion, American actor (Avatar: The Way of Water), born in Blacksburg, Virginia
About 2004
How Old? 19 or 20 years old
Generation: Generation Z
Chinese Zodiac: Goat/Sheep (Feb 1, 2003 - Jan 21, 2004),
Monkey (Jan 22, 2004 - Feb 8, 2005)
Greatest Generation
Silent Generation
Baby Boomer
Generation X
Millennial
Generation Z