"While he had injury issues this year, Russell has given us good service in his six seasons after coming to the club as a young player with potential,'' Warriors general manager football operations Dean Bell said. "We appreciate what he achieved with the Vodafone Warriors and wish him all the best as he looks to make a new start in the NRL.''
The Knights had been in the market for a prop and had initially targeted Melbourne youngster Mitchell Garbutt, a Newcastle junior who played in their under-20s in 2008 and 2009, but Packer offers both youth and experience.
The Warriors have plenty of propping options, with Suaia Matagi, Charlie Gubb, Sione Lousi, Sam Lousi and Albert Vete in the frame to join Ben Matulino, Jacob Lillyman and Sam Rapira in the first-grade side.
"I thoroughly enjoyed my time at the Warriors since joining the club in 2007 but to have the opportunity to play at the Knights and to be coached by Wayne Bennett is special,'' said Packer, who will relocate to Newcastle with his young family ahead of pre-season training in November.
"I look forward to joining the Knights in the pre-season and assisting the Knights' premiership ambitions.''