The 27-year-old, a former New Zealand Under-21 international, made his Crusaders debut in 2009 and also captains Tasman in the Air New Zealand Cup provincial competition.
He said: "This is a really exciting move for me. I am looking forward to a different challenge in England.
"It has been difficult to be behind such a great player as Richie McCaw, and my opportunities to start games for the Crusaders have obviously been less than I would have liked."
Wasps chief executive Chris Thomas added: "Jonathan has excellent leadership qualities, and having featured for a number of seasons in one of the best club sides in the world, he will bring a lot of top experience to the squad."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The Barbarians are one of the top invitational rugby sides with a long history and classic rugby jersey.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
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The Lions are ready to get their Australia tour underway. They arrive in Perth on Monday.
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The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.
