Former France fly-half Frédéric Michalak will leave Toulon at the end of the season to join newly-promoted Lyon.
Michalak, 33, called time on his international career after last year's Rugby World Cup, having won 77 caps.
During his time with Toulon since 2012 he has been part of the club's sustained success, winning three European Cups and a Top 14 title.
Lyon have been comfortable winners of this season's ProD2 title in France and have already signed up Lions lock Franco Mostert, Toulon full-back Delon Armitage and Rebels fly-half Mike Harris for next season.
Michalak said: "I want to give my maximum before my career ends. This is a club with a lot of ambition."
Lyon will become Michalak's fourth club having turned out for Toulouse, Super Rugby's Sharks and Toulon.