The 26-year-old, who has won 56 caps for the Azzurri, will join the Aviva Premiership club from Treviso.
Speaking after the signing was announced, Sale ruby director Steve Diamond told the club's official website: "Luke is an exceptional international full-back.
"He is a genuine 15 and great under the high ball. Luke will bring a lot of experience with him and will complement and help push our standards.
"With qualifying for the new European competition, we have now brought in four Internationals to replace the lads who are leaving. Luke is also a very competent goalkicker."
McLean, who was born in Australia, spent two years with Calvisano before joining fellow Italian club Treviso in 2009.