The former winger, who won 10 Scotland caps during his playing career, joined Sale’s coaching team in 2023.
Last season, he took charge of the team during their Prem Rugby Cup matches and was defence coach as the Sharks finished third in the league.
His work came to England’s attention and he has had a particular emphasis in his role on players’ contact skills and working with the back three.
Sale director of rugby Alex Sanderson said: “Byron’s contribution to the club as a player and then as a coach has been huge.
“He’s been a massive part of what we’ve achieved, and who we are as a club, and his influence will be felt in whatever we achieve in the future.”
