De Luca, who will move to the Aviva Premiership club from Biarritz, has won 43 caps since making his Test debut during the 2008 Six Nations.
He will arrive initially on a short-term contract as Wasps look to bolster their midfield options following three retirements and injuries suffered by Kurtley Beale and Alapati Leiua.
De Luca, 32, joined Biarritz from Edinburgh in 2014, and Wasps rugby director Dai Young said: “While we have initially signed Nick on a short-term deal as injury cover, we are not ruling out a longer-term agreement.
“I have only seen and heard good things about Nick in terms of his attitude, ability and application.
“He has already proven himself as a top professional and an international rugby player, and I am looking forward to working with him when he joins up for pre-season.”