- Sep 1 Joseph Trohman, American guitarist (Fall Out Boy - "This Ain't a Scene, It's an Arms Race"), born in Hollywood, Florida
- Sep 1 Ludwig Göransson, Swedish Emmy, Grammy, and Academy Award-winning composer and record producer (The Mandalorian; Childish Gambino; Black Panther), born in Linköping, Sweden
- Sep 2 Jack Peñate, British rockabilly singer-songwriter and musician (Matinée), born in London, England
- Sep 3 Garrett Hedlund, American actor, born in Roseau, Minnesota
- Sep 4 Camila Bordonaba, Argentine actress and singer-songwriter, born in El Palomar, Argentina
- Sep 4 Hamish McIntosh, Australian football player, born in Lavington, Australia
- Sep 7 Vera Zvonareva, Russian tennis player (4 x Grand Slam doubles titles; US Open, Wimbledon 2010 runner-up; Federation Cup 2004, 08), born in Moscow, Russia
- Sep 8 Peter Whittingham, English footballer, born in Nuneaton, England
- Sep 8 Vitaly Petrov, Russian racing driver (Renault F1 Team in 2010), born in Vyborg, Soviet Union
- Sep 9 Farrah Gray, American entrepreneur and author (Reallionaire), born in Chicago, Illinois
- Sep 9 James Hildreth, English cricketer, born in Milton Keynes, United Kingdom
- Sep 10 Matthew Followill, American alternative-rock backing vocalist and musician (Kings of Leon - "Use Somebody"), born in Oklahoma City, Oklahoma
- Sep 12 Taylor Jenkins, American basketball head coach (Memphis Grizzlies 2019), born in Arlington, Texas
- Sep 13 Nabil Abou-Harb, Arab-American filmmaker, born in Marietta, Georgia
- Sep 14 Adam Lamberg, American actor (The Lizzie McGuire movie), born in NYC, New York
- Sep 14 Ayushmann Khurrana, Indian actor and singer (Vicky Donor), born in Chandigarh, India
- Sep 14 Melissa McGhee, American rock singer (American Idol, season 5), born in Tampa, Florida
Prince Harry (38 years old)
Sep 15 Duke of Sussex, 5th in British succession, born in London, England
- Sep 16 Katie Melua, Georgian-British singer (Piece by Piece), born in Kutaisi, Georgian SSR, USSR
- Sep 16 Sabrina Bryan, American actress and singer (The Cheetah Girls), born in Yorba Linda, California
- Sep 17 Eugenia Volodina, Russian supermodel
- Sep 18 Anthony Gonzalez, American politician (Rep-(R)-Ohio 2019-) and football player, born in Cleveland, Ohio
- Sep 18 Dizzee Rascal [Dylan Kwabena Mills], English rapper (Boy in da Corner), born in London, England
- Sep 19 Eamon [Doyle], American pop singer ("F*ck It (I Don't Want You Back)"), born in Staten Island, New York City
- Sep 19 Kevin Zegers, Canadian actor and model, born in Woodstock, Ontario
- Sep 21 Benjamin Wildman-Tobriner, American swimmer
- Sep 21 Wale [Olubowale Akintimehin], American rapper of Nigerian heritage (The Gifted), born in Washington, D.C.
- Sep 22 Laura Vandervoort, Canadian actress (Haven, Smallville), born in Toronto, Ontario
- Sep 22 Misha Green, American screen writer, director and producer (Lovecraft Country), born in Sacramento, California
- Sep 22 Ross Jarman, English drummer (The Cribs), born in Wakefield, England
- Sep 22 Theresa Fu, Hong Kong singer and actress
- Sep 22 Thiago Emiliano da Silva, Brazilian football player (Paris Saint-Germain, Brazil national team), born in Rio de Janeiro
- Sep 23 Anneliese van der Pol, Dutch-American actress (That's So Raven & Raven's Home -"Chelsea"), born in Naaldwijk, Netherlands
- Sep 23 Louie Stephens, American rock keyboard player and singer (Rooney)
- Sep 23 Matt Kemp, American MLB baseball outfiekder, 2006-20, 3X All-Star, 2X Gold Glove (Los Angeles Dodgers, and four other teams), born in Midwest City, Oklahoma
- Sep 23 Nathan Jendrick, American fitness trainer, health instructor, and author, born in Tacoma, Washington
- Sep 24 Szilvia Molnar, Swedish writer
- Sep 24 Taylor Eigsti, American Grammy Award-winning jazz pianist, composer ("Lucky To Be Me"), orchestrator, and educator, born in Menlo Park, California
- Sep 25 Matt Carle, American ice hockey player, born in Anchorage, Alaska
- Sep 26 Keisha Buchanan, British pop and R&B singer (Sugababes - "Round Round"; "Push the Button"), born in Kingsbury, England
- Sep 26 Thore Schölermann, German actor, born in Iserlohn, Germany
Avril Lavigne (38 years old)
Sep 27 Canadian singer-songwriter (Complicated, Sk8er Boi), born in Belleville, Ontario
- Sep 27 Cyrille Dubois, French operatic tenor and lieder singer, born in Ouistreham, France
- Sep 27 John Lannan, American baseball player
- Sep 27 Paul Bevan, Australian rules footballer
- Sep 28 Melody Thornton, American singer and dancer
- Sep 28 Ryan Zimmerman, American baseball player
- Sep 29 Adriene Mishler, American yoga teacher (Yoga with Adriene on YouTube), born in Austin, Texas
- Sep 29 Per Mertesacker, German football player (Arsenal), born in Hanover, West Germany
- Sep 30 T-Pain [Faheem Rasheed Najm], American rapper (Epiphany), born in Tallahassee, Florida
About September 1984
How Old? 38 years old
Generation: Millennial
Leap Year: Yes