Christina Parie was born on February 10, 1996 to Jim and Mary Papoulias, and came from Castle Hill, New South Wales. Born as the middle child, Parie has an older sister, Alexa, and a younger brother, Jordan. She is the only member of her family that sings, and has cited Avril Lavigne, Kelly Clarkson, Pink and The Cranberries as her musical influences. Parie began playing the piano at the age of nine and the guitar at the age of fourteen. She was also the lead singer of the five-piece band Losing Sight, who performed regularly at cafes, festivals and venues across Sydney. During years eight to ten, Parie attended Mount St Benedict College in Pennant Hills, New South Wales. After finding it difficult to continue school in year eleven because of the fame she achieved on The X Factor, Parie quit school to pursue her music career.

2011: The X Factor (Australia)

Parie auditioned for the third season of The X Factor in 2011, singing Kelly Clarkson's "I Do Not Hook Up" in front of judges Ronan Keating, Guy Sebastian, Natalie Bassingthwaighte and Melanie Brown. Keating described Parie's stage presence as "incredible" while Brown said, "I'm surprised a record company hasn't tried to snap you up already." Sebastian commented, "you are complete, people in the record industry look for people like you." Parie progressed through to the bootcamp stage where she was placed into the Under-25 Girls category and was mentored by Brown. After bootcamp, she progressed through to the home visits stage where the Under-25 Girls travelled to Hollywood, California to perform in front of Brown and guest judge Melanie Chisholm. During the last day of home visits, Brown selected Parie, along with Tyla Bertolli and Jacqui Newland, for the live finals—a series of ten weekly live shows in which contestants are progressively eliminated by public vote. In week seven, Parie landed in the bottom two for the first time with Reece Mastin, following her rendition of David Guetta's "When Love Takes Over". Parie was eliminated after Keating, Sebastian and Bassingthwaighte chose to save Mastin. She was the last contestant from the Under-25 Girls category to be eliminated. Coling Vickery of the Herald Sun called it "one of the biggest shocks" of the season.

2012: Record deal and 16 & Unstoppable

In January 2012, Parie and fellow X-Factor contestant Johnny Ruffo were supporting acts for Reece Mastin's first headlining Australian tour. In March 2012, she posted a cover of Simple Plan's Jet Lag on her YouTube page. The cover's success prompted the band to invite her to tour with them for a few shows in Australia alongside We the Kings. While on tour, Parie contributed featured vocals to Jet Lag. Shortly after, in June 2012, it was announced that Parie had signed a record deal with Warner Music Australia. Her debut single "16 & Unstoppable" was released digitally on 13 July 2012, which debuted and peaked at number 69 on the ARIA Singles Chart. A five-track extended play also titled 16 & Unstoppable was released on 27 July 2012. The EP's third track "Back to Life" was written by The Veronicas. Parie performed "16 & Unstoppable" at Nickelodeon Australia's first Slimefest concert on 15 September 2012.