Lauren Arbuckle's ex-fiance sued her after their relationship ended because of squabbles over wedding finances.
Devin Sherrington sued for the return of the ring and a $6,000 loan after the three-year relationship fell apart.
A Nova Scotia court found that although she ended the relationship, it was not her idea to break up so she did not have to return the gift.
Small claims adjudicator Gregg Knudsen said that since the 3.25 carat diamond ring was gifted on the condition the two would marry, the entire matter rested on who ended the engagement.
If Ms Arbuckle, a hairstylist and make-up artist, ended it, then she must relinquish the gift, he said. However, if Mr Sherrington, a personal trainer, broke it off, then the gift was rightfully hers.
The couple had been engaged for one year before deciding to call it quits because the two could not agree about how to pay for the wedding.
Ms Arbuckle wanted a lavish affair, while Mr Sherrington wanted something more cost-conscious.
He didn't believe his fiancee could afford her half of the wedding cost, the court heard, and feared he would get stuck paying for the whole bill.
He suggested postponing the wedding but she did not want to. Finally, she decided to end the relationship.
At first, Mr Sherrington told Ms Arbuckle she could keep the ring, text messages show. But later, he asked for it back, as well as money he says he loaned her for a trip to Mexico.
Ultimately, Mr Knudsen found that it was Mr Sherrington who called off the engagement, and so the ring rightfully belongs to Ms Arbuckle - although he also ruled that she had to pay him back about C$3,000 for the Mexico trip.
"I find the postponement was an indefinite postponement, sufficient to treat the engagement as over. Ms. Arbuckle may have ended the relationship but Mr. Sherrington ended the engagement," he said.
But Ms Arbuckle's victory is short-lived, as she has had to file for bankruptcy and all her assets - including the ring - are being held by a trustee.
A Canadian judge has ruled that a woman can keep her C$19,000 ($14,300, Â£11,210) engagement ring.