The 24-year-old, who moved to the club before the 2012 campaign, has committed to the outfit after scoring 10 tries in 27 matches last season.
"I am over the moon with the extension as it gives me a bit more security," Kear told the club's official website. "I love the Bulls and it was a dream for me when I first came here.
"I am settled here now and am really enjoying myself, so I'm delighted to sign for another year.
"My main aim this coming season will be to stay injury-free, play every game again and match the form I showed this year."
Kear initially signed a three-year deal when he joined the club from Crusaders.