| 108241 | September 21 | Birth | 1979 – Jaymee Ong, Australian model and actress |
| 108242 | September 21 | Birth | 1980 – Stacy Clark, American singer-songwriter |
| 108243 | September 21 | Birth | 1980 – Robert Hoffman, American actor, dancer, and choreographer |
| 108244 | September 21 | Birth | 1980 – Kareena Kapoor Khan, Indian actress and singer |
| 108245 | September 21 | Birth | 1980 – Nyree Kindred, Welsh swimmer |
| 108246 | September 21 | Birth | 1980 – Aleksa Palladino, American actress and singer |
| 108247 | September 21 | Birth | 1980 – Autumn Reeser, American actress |
| 108248 | September 21 | Birth | 1980 – Tomas Scheckter, South African race car driver |
| 108249 | September 21 | Birth | 1981 – Nicole Richie, American actress, singer, fashion designer, and author |
| 108250 | September 21 | Birth | 1981 – Rimi Sen, Indian actress |
| 108251 | September 21 | Birth | 1982 – Eduardo Azevedo, Brazilian race car driver |
| 108252 | September 21 | Birth | 1982 – Marat Izmailov, Russian footballer |
| 108253 | September 21 | Birth | 1982 – Danny Kass, American snowboarder |
| 108254 | September 21 | Birth | 1982 – Parvati Shallow, American reality show contestant, winner of Survivor: Micronesia |
| 108255 | September 21 | Birth | 1982 – Christos Tapoutos, Greek basketball player |
| 108256 | September 21 | Birth | 1982 – Rowan Vine, English footballer |
| 108257 | September 21 | Birth | 1983 – Fernando Cavenaghi, Argentinian footballer |
| 108258 | September 21 | Birth | 1983 – Kristian Gidlund, Swedish drummer and journalist (Sugarplum Fairy) (d. 2013) |
| 108259 | September 21 | Birth | 1983 – Maggie Grace, American actress |
| 108260 | September 21 | Birth | 1983 – Greg Jennings, American football player |
| 108261 | September 21 | Birth | 1983 – Joseph Mazzello, American actor, director, producer, and screenwriter |
| 108262 | September 21 | Birth | 1983 – Anna Meares, Australian cyclist |
| 108263 | September 21 | Birth | 1984 – Wale, American rapper |
| 108264 | September 21 | Birth | 1984 – Ben Wildman-Tobriner, American swimmer |
| 108265 | September 21 | Birth | 1985 – Justin Durant, American football player |
| 108266 | September 21 | Birth | 1985 – Maryam Hassouni, Dutch actress |
| 108267 | September 21 | Birth | 1986 – Faris Badwan, English singer-songwriter (The Horrors and Cat's Eyes) |
| 108268 | September 21 | Birth | 1986 – Lindsey Stirling, American violinist and composer |
| 108269 | September 21 | Birth | 1987 – Jimmy Clausen, American football player |
| 108270 | September 21 | Birth | 1987 – Marcelo Estigarribia, Paraguayan footballer |