The Wolves have paid a transfer fee of £150,000 to Hull to release Westerman from his contract.
Westerman, 25, broke onto the scene in 2007 with Castleford Tigers in their National League One campaign. He remained with the Tigers on their return to the Super League for the next three seasons before signing for Hull FC for an undisclosed fee in 2010 ahead of the 2011 campaign.
He is equally effective through the middle as well as out wide and has gone on to make 128 appearances for the Black and Whites – including the 2013 Challenge Cup final at Wembley – crossing for 29 tries, kicking 58 goals and one drop goal.
Having missed out on England’s 2008 World Cup campaign through a late injury he went on to play second row forward for England against Cumbria in an 18-18 draw in 2010. He was then selected in the England 2014 Four Nations squad and played loose forward in the 32-26 win over Samoa. Hooker Daryl Clark also made his England debut in the same match.
“We are delighted to have signed Joe for the next three seasons. He is another example of our commitment to investing in young, British talent. He will be an ideal fit with many facets to his game and will complement the quality English players and upcoming juniors already in our 2016 squad. He is a young player with a lot of potential having already had some international recognition. We look forward to his further development and working with him next year.”
Westerman said: “It’s a new challenge for me. It’s a big club and one that’s on the up. Hopefully next year we can win some silverware and compete at the top of the table. That’s my ambition, it’s a good enough club and there’s no reason why we shouldn’t be contesting for medals.
“When I was younger and with England I worked under Tony and I learnt a lot then so I am looking forward to learning from him again. I’m good mates with Daryl Clark so it will be good to play with him again, obviously Tom Lineham – who has moved over too – and I played with Chris Hill with England as well, so I’m just looking forward to getting started and settling in.”