Wasps sign All Black prop from Hurricanes
Toomaga-Allen is the second All Black signed by Wasps this week following their announcement on Wednesday that centre Malakai Fekitoa will join them from Top 14 side Toulon next season.
"To bring someone of Jeff's calibre to the club is fantastic news," said Wasps rugby director Dai Young.
The 28-year-old forward earned his only New Zealand cap against Japan in 2013, and he was also a member of New Zealand's Rugby Championship squad four years later.
"Jeff is a solid scrummager, while also being strong in defence. And like most New Zealanders, he is gifted with ball in hand, so he's a terrific all-round player," added Young.
"We are looking forward to him joining us next season, as he will provide a real wealth of experience to the front-row."
Toomaga-Allen said: "I want to help the club compete at the very top of the Premiership and European competitions, and hopefully I can be part of something special in winning trophies."