She was born Dinah Jane Milika Ilaisaane Hansen in Santa Ana, California on June 22, 1997  to parents Gordon and Milika Fot'aika. She is the oldest of six siblings. She is of Polynesian, Tongan and Danish descent. Dinah grew up in a 4-bedroom home with 23 other people. 
At an early age she began to have a curiosity for music that blossomed into a devotion for singing. She was often invited to perform at various events around Orange County while growing up.
The X Factor
She auditioned for the second season of The X Factor, receiving positive reviews from all the judges before she was promoted to the Bootcamp round of the competition.
Hansen auditioned for The X Factor singing "If I Were a Boy" by Beyoncé, during which L.A. Reid stated that she "took the song to places that even Beyoncé didn't". She cites Ciara, Beyoncé, Leona Lewis, Mariah Carey and Etta James as her musical influences.
During the final round of bootcamp, Hansen sang "Stronger (What Doesn't Kill You)" by Kelly Clarkson with another contestant. She forgot part of the song throughout the performance. Due to this, Hansen was eliminated as a solo performer, but was later brought back into the competition to form Fifth Harmony.
A critical stumble led to her elimination as a solo singer, but she was brought back as part of a the girl group LYLAS with other members just as talented. The group would be renamed Fifth Harmony. 
Though Fifth Harmony would place third in the competition, they would continue to perform afterward. Their debut EP, Better Together, was released in 2013. Within its first week, it reached the No. 6 position on the Billboard 200. Their debut album, Reflection, was released in 2015. The song “Worth It” became the group’s first Top 15 hit, going on to earn Double Platinum certification.