The 15-year-old, who writes all her own songs, was named the winner last night after public votes from the previous Sunday's grand final were counted and collated.
Clara beat more than 5000 acts.
Wellington's Jessie Hillel was named runner-up on the TVNZ show and Auckland teenager Evan Sinton was placed third.
Told she had won after 12 weeks of performances, Clara was briefly overcome with tears and told the judges Jason Kerrison, Rachel Hunter and Ali Campbell that she felt as if she were dreaming.
"This whole journey has been incredible," the Year 11 Marlborough Girls' College student said. "Can someone pinch me, please?"
She's been singing since she was a toddler, as well as playing the acoustic guitar and ukulele. Clara also has a catalogue of more than 50 original songs, mostly based on the books she reads.
"I think the music I write is really special and different," Clara said.
"It comes from the heart and I'm totally committed to it. I have my own style and to be able to share that is a beautiful thing."
After her first audition, Campbell described her as a serious talent and during the semifinals, Hunter told her she "oozed" the superstar factor. As part of her prize Clara won $100,000 and a 2013 Toyota Corolla. Her first single Where Do You Find Love? will be released before Christmas.
