Clermont, who finished runners up in last season's Heineken Cup, beat off a host of potential suitors to sign the 25-year-old.
And Lhermet insists that in Davies they have captured one of the world's best centres just as he enters his prime.
"We are delighted to welcome Jonathan to the next season," he said.
"His profile fits perfectly to the game we play and he will bring us a lot.
"Despite his young age, he has a huge experience of top level matches and is one of the world's best players in his position.
"He will be an asset to our team. Jonathan decided to leave Wales for a new adventure, and we are happy that he'll be playing in yellow and blue.
"We're sure that his class and determination will help us win new trophies in the years to come."