Bennett stared for Wales at the World Cup and started the opening two matches of the all conquering Six Nations campaign, before injury ruled him out of the rest.
The Gwent-born star was forced to undergo Achilles surgery and is battling to be fit for the beginning of the new season where he hopes to help the French club bounce back from relegation.
"It's a new experience for me, the first time I have changed club," said Bennett.
"But all is well since I arrived in Lyon. My team-mates have been very welcoming and helpful to me. In addition, it is nice here.
"It's a new adventure for me and the goal is to go straight back up. The club has ambition, evidenced by the fact that few players left in the off season.
"I cannot wait to start the season. I should be ready for it. I am very pleased and excited to be here."
Bennett will link up with a familiar face at Lyon, in former Ospreys team-mate and South Africa star Ricky Januarie, who has also joined the club.
Lyon are hoping to earn an automatic return to the Top 14 following a disappointing season that saw them relegated to PRO D2.