- Sep 13 Destiny Rogers, American pop and R&B singer ("Tomboy"), born in Lodi, California
- Sep 28 Olivia Jade Giannulli, American Youtuber (daughter of Mossimo Giannulli and Lori Loughlin)
- Sep 29 Juan Valentín Urdangarín y de Borbón, Spanish royal, son of Infanta Cristina de Borbon, born in Barcelona, Spain
About September 1999
How Old? 23 years old
Generation: Generation Z
Leap Year: No