The 28-year-old Tonga international joined the Bulls from Parramatta Eels on a 12-month deal 18 months ago and signed a two-year extension late last year.
However, that contract included a clause enabling him to leave the club at the end of this season and the Bulls have now secured Manuokafoa's services until the end of 2015.
"I want to be a part of the Bulls moving forward under Franny (Cummins) and that's why I've signed for another two years," said Manuokafoa, who is expected to be in Tonga's squad for this year's World Cup.
"There are a lot of very good homegrown players at the club and it's up to the senior players such as myself to help them come through.
"I'm just very happy to extend my stay at Bradford. My wife, my son and I love it here. We love the club and are very settled in the area."
The powerful front rower, who has also played for South Sydney and North Queensland, missed five matches recently with a broken thumb but will make a third consecutive appearance at Wigan as the Bulls look to end a five-match losing run.
Bradford coach Cummins said: "You need a strong pack to take you forward and to bring in other people such as Garreth (Carvell) is great but Nas is very important for us too.
"He's improved again this year despite the setback of breaking his thumb.
"But he had a good off-season and I reckon he's going to be even better next year too."
- Sports & Recreation
- Parramatta Eels