The Aviva Premiership club have moved for Cusiter on a two-year deal.
He will move to Sale from Glasgow Warriors for next season, filling the vacancy left by former Wales number nine Dwayne Peel, who is moving to ambitious Championship club Bristol.
Cusiter, 30, has won 66 caps for Scotland and made one Test match appearance on the British and Irish Lions’ 2005 tour to New Zealand.
He previously played with former Scottish professional team Border Reivers before having a two-year stint at French club Perpignan, He joined Glasgow in 2009.
“Chris is a great signing for the club,” Sale rugby director Steve Diamond said.
“We have signed him to replace Dwayne Peel, who is leaving us after six years at the club, and we know that Chris will be the quality replacement we need.
“A lot of credit for the signing must go to (Sale coach) Bryan Redpath, who knows Chris well.
“Chris will join us in the close season, and we look forward to him arriving.”
Cusiter becomes Sale’s second major new signing for next term, following his fellow Scotland international Nathan Hines, who will move to the Sharks from French giants Clermont Auvergne.
Cusiter is excited about the prospect of completing the set of playing in Europe’s top three league competitions.
“It was a big deal for me coming coming back to Scotland and I’ve had a fantastic time at Glasgow,” he said.
“Not many players get the opportunity to play in the Top 14, RaboDirect PRO12 and Aviva Premiership, so I’m excited about that.”