Authors born in 1984
- Jesus David Torres Singer, 1984
- Jillian Bell Actress, 1984
- Jillian Murray Actress, 1984
- Jimmy Napes Singer-Songwriter, 1984
- Joe Gilgun Actor, 1984
- Joe Trohman Musician, 1984
- Joel Smallbone Singer, 1984
- John Corey Whaley Author, 1984
- John David Washington Actor, 1984
- John Gallagher, Jr. Actor, 1984
- John Zimmer Businessman, 1984
- Johnathan Joseph American Football Player, 1984
- Johnny Christ Musician, 1984
- Johnny Weir Figure Skater, 1984
- Jon Lester Baseball Player, 1984
- Jonathan Anderson Fashion Designer, 1984
- Jonny Diaz Singer, 1984
- Jorge Masvidal Mixed Martial Artist, 1984
- Josephine de La Baume Actress, 1984
- Josh Trank Film Director, 1984
- Joshua Henry Actor, 1984
- Judith Hill Singer-Songwriter, 1984
- Julia Natasha Stone Singer-Songwriter, 1984
- Justin Moore Singer, 1984
- Kaitlin Doubleday Actress, 1984
- Kalki Koechlin Actress, 1984
- Karan Mahajan Novelist, 1984
- Karen Civil Strategist, 1984
- Karim Kharbouch Artist, 1984
- Karishma Tanna Actress, 1984
- Karolina Kurkova Model, 1984
- Kass Morgan Author, 1984
- Kate McKinnon Actress, 1984
- Katharine McPhee Actress, 1984
- Katie Melua Singer-Songwriter, 1984
- Katie Uhlaender Racer, 1984
- Katy Perry Singer, 1984
- Kay One Rapper, 1984
- Keisha Buchanan Singer-Songwriter, 1984
- Kelli Garner Actress, 1984