Kaci Roman was born Jessica Kaci Roman on April 17, 1982 in Chicago, Illinois. She is the daughter of Jillian Roman, an event coordinator; and Robert Roman, a lawyer. She has one older brother, Justin Marino Roman, who is also a singer/songwriter. Kaci also owns a Chihuahua named Hayley.
Kaci grew up in Wilmette, Illinois, a northern suburb of Chicago, until she graduated high school in 1999. After graduating high school, she toured Europe with her brother, who was on the road touring with his group, Vi3, with the Backstreet Boys. It was there that Kaci met and became involved romantically with Backstreet Boy A.J. McLean. The two dated throughout the European leg of the Backstreet Boys' "Into the Millennium" tour, and continued to see each other after returning to the States after the European leg of the tour ended.
In September 2000, a month after returning from Europe, the Roman family moved to Florida in order for both Justin and Kaci to pursue their dream of being recording artists. In April 2003, shortly after her 21st birthday, Kaci signed to Latium Entertainment.
Currently, Kaci is in the studio recording her debut album, which is being recorded in both Florida and California.
Kaci is currently dating her high school sweetheart, Fall Out Boy bassist/lyricist, Pete Wentz.