Ruth Farrar from Leeds will put the money towards her dream of publishing her stories, which centre around a yellow teddy visiting 11 countries.
One particular story focuses on saving for young people.
She was awarded the funds after receiving 60% of a 500-strong public vote through social media after sharing her reasons for saving with the society.
Farrar said: “I have been interested in creative writing since I was a child.
“I first attempted to write the book four years ago. It was a story about a yellow teddy who visited 11 different countries.
“However, after research, I found that the story was far too long and I therefore decided to split it into four separate stories.
“By using a computer package called Captivate and animating certain images from the books, I have also created interactive e-learning material which is both educational as well as entertaining.”
She added: “When I discovered I had made the final three for ‘Save Interesting’, I wrote a story especially for Leeds Building Society also featuring Yellow Teddy.
“The aim of this story was to encourage young children to work independently towards their own savings goals.”
Farrar heard about the campaign at her local Leeds Building Society branch in Moortown and shared her savings story through its microsite.
Kim Rebecchi, distribution and marketing director at Leeds Building Society, said: “Throughout the ‘Save Interesting’ campaign we heard from people with great savings stories to tell.
“All, like our winner Ruth Farrar, were saving for something that's very close to their heart.
“Everyone has something they really want to save up for and the dedication people can show to achieve their goals is inspiring.
“By sharing the stories of these savers, we hope to inspire more people to start putting money aside for the things they really want in life and celebrate their focus and determination in working towards achieving their goals.”