The 28-year-old Newcastle Knights forward will arrive at MS3 Craven Park ahead of the 2013 Super League campaign, along with the club's other confirmed recruits, Cory Paterson (North Queensland) and Sean Gleeson (Salford).
The Auckland-born Tuimavave spent eight seasons with New Zealand Warriors before joining Newcastle ahead of the 2010 season. He played under current Hull KR coach Craig Sandercock at the Knights.
Tuimavave represented the Junior Kiwis and was a member of the Kiwis' 2008 World Cup-winning squad.
"I've always wanted to play over in the Super League and this is a great opportunity for me to fulfil that ambition," he said.
"I worked with Sandy (Craig Sandercock) at the Knights last year. We have a good relationship and I think he can get the best out of me, as he did last season."