- Sep 1 Joseph Trohman, American musician (Fall Out Boy)
- Sep 2 Jack Peñate, English singer and musician (Matinée), born in London, England
- Sep 4 Camila Bordonaba, Argentine actress and singer-songwriter, born in El Palomar, Argentina
- Sep 10 Matthew Followill, American alternative-rock backing vocalist and musician (Kings of Leon), born in Oklahoma City, Oklahoma
- Sep 14 Melissa McGhee, American rock singer (American Idol, season 5), born in Tampa, Florida
- Sep 14 Ayushmann Khurrana, Indian actor and singer (Vicky Donor), born in Chandigarh, India
- Sep 16 Sabrina Bryan, American actress and singer (The Cheetah Girls), born in Yorba Linda, California
- Sep 16 Katie Melua, Georgian-British singer (Piece by Piece), born in Kutaisi, Georgian SSR, USSR
- 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 21 Wale [Olubowale Akintimehin], American rapper of Nigerian heritage (The Gifted), born in Washington, D.C.
- Sep 22 Eduardo Rubio, Mexican pilot and pianist
- Sep 22 Theresa Fu, Hong Kong singer and actress
- Sep 22 Ross Jarman, Drummer The Cribs
- Sep 23 Louie Stephens, American rock keyboard player and singer (Rooney)
- Sep 26 Keisha Buchanan, English singer (Sugababes), born in Kingsbury, United Kingdom
Avril Lavigne
Sep 27 Avril Lavigne, Canadian singer-songwriter (Complicated, Sk8er Boi), born in Belleville, Ontario

Avril Lavigne
- Sep 28 Melody Thornton, American singer and dancer
- Sep 30 T-Pain {Faheem Rasheed Najm], American rapper/singer (Epiphany), born in Tallahassee, Florida
About September 1984
How Old? 36 years old
Generation: Millennial
Leap Year: Yes