Capped 77 times for his adopted nation, the 37-year-old Australian opened his union career with Manly before emigrating in 1999, since when he has turned out in the colours of Gala, Edinburgh, Perpignan, Leinster and his current French club.
A Heineken Cup winner with Leinster in 2009/10, the British and Irish Lion is seen as a complementary addition to Steve Diamond's Aviva Premiership side.
"Nathan is a world-class player and will fit in well with us at Sale Sharks," said the coach. "He has vast experience playing at the highest level and is a regular starter at Clermont. Last weekend he was magnificent in helping his team beat Racing Paris. The forwards at Sale Sharks have played well this season and adding Nathan to the group will be a big boost to us."