Tuala, who can play at either centre or wing, has become a mainstay for the Knights since his move to the club ahead of the 2020 season.
The new two-year deal will see Tuala remain in the Hunter until at least the end of the 2023 season.
The 23-year-old, who was born in Cairns lined up at Centre for the first 19 rounds of this season, before shifting to the wing where he found immediate success.
He scored seven tries in his first four games on the wing and ended up with 11 in six games, including a hat-trick against the Parramatta Eels in an elimination final loss which ultimately ended their season.
A solid starting option for the Knights though, Tuala's signature was surprisingly delayed to well beyond the completion of the current season, and it was beginning to be questioned whether he would be re-signed, particularly the recent triple re-signing of Chris Randall, Jack Johns and Phoenix Crossland.
Head of recruitment Clint Zammit said Tuala was coming off a career-best season.
“Enari worked hard on the things he needed to change, he played in every game for the Knights in 2021, resulting in a career-best season,” Zammit said.
“His extension adds real depth to our outside backs, covering both wing and centre.
“If he continues to work hard, especially in the pre-season, we believe his game can improve again 2022.”