List of Famous people who are 21

Matthew Boling is an American track and field athlete specializing in the sprints and long jump. He won four gold medals at the 2019 Pan American U20 Championships in the 100 m, 200 m, 4 × 100 m relay and 4 × 400 m relay, and helped set world under-20 records in both of the relay races for the United States. He also ran in the semi-final for the American 4 × 400 m relay team at the 2018 World U20 Championships that went on to earn silver in the final.

Thomas F. Kelly is an American musician, best known for his songwriting partnership with Billy Steinberg. Steinberg and Kelly co-wrote numerous hit songs for popular music artists, including five number-one singles on the Billboard Top 100 chart in the 1980s.

Mikayla Victoria Simpson, better known as Koffee, is a Jamaican reggae singer, songwriter, rapper, deejay and guitarist from Spanish Town, Jamaica. She released her debut single "Burning" in 2017, and in 2019 signed with Columbia Records. Her 2019 EP Rapture won the Grammy Award for Best Reggae Album at the 62nd Annual Grammy Awards, making Koffee the youngest person and only woman to be awarded in the Best Reggae Album category. Her most recent album Gifted was released in March 2022.

Nhat Nguyen is an Irish badminton player. Born in Vietnam, Nguyen left the country for a new life in Dublin, Ireland along with his parents and older sister, when he was six years old, and then, he started playing badminton at the local club with his father. He was the gold medalist at the 2016 European U17 Championships in the boys' singles event, and also won the bronze medal in the doubles event partnered with Paul Reynolds. At the same year, he clinched the men's singles title at the Irish National Championships. Nguyen won his first senior international title at the Polish International in the men's doubles event with Reynolds, after that the men's singles title at the Welsh International.

Jalen Evander Lecque is an American professional basketball player for the Indiana Pacers of the National Basketball Association (NBA). A consensus four-star recruit and former NC State commit, Lecque chose to forgo college basketball and immediately entered the 2019 NBA draft.

Maximillian James Aarons is an English professional footballer who plays for Championship club Norwich City. He is primarily a right-back, but can also play as a left-back.

Jayden Ian Bogle is an English professional footballer who plays for Premier League club Sheffield United.

Ribka Sugiarto is an Indonesian badminton player specializing in doubles. Born in Karanganyar, she was selected to join the Djarum club in 2013. Sugiarto was the gold medalist at the 2018 Asian Junior Championships partnered with Febriana Dwipuji Kusuma, and won her first senior international title in 2019 Indonesia Masters, a Super 100 tournament with Siti Fadia Silva Ramadhanti.

Pierre Kalulu Kyatengwa is a French professional footballer, who plays for Serie A club A.C. Milan as a defender; mainly a right-back, he can also play in central defense.

Mark Bridges is an American costume designer. He frequently collaborated with Paul Thomas Anderson for each films. Bridges has been nominated four times for an Academy Award for Best Costume Design, winning two for The Artist (2011) and Phantom Thread (2017). For the latter, he won a Jet Ski and a stay in Lake Havasu City, Arizona resort, as a part of the Academy Awards telecast stunt to award the Oscar recipient who gave the shortest acceptance speech. His other awards include two BAFTA Awards for Best Costume Design for his designs for The Artist and Phantom Thread.