Christophe Urios said on Wednesday he was "thrilled" to take over from sacked former New Zealand back-rower Jono Gibbes as two-time French Top 14 winners Clermont's head coach.
Gibbes, 45, was fired on Monday after less than two years in the job with the club in 10th place in the league, with just one win in their last five games in all competitions.
Urios, 57, was let go by Bordeaux-Begles in November after a poor start to the season having led them to the semi-finals during the previous two campaigns.
"I'm thrilled to announce my arrival as Clermont head coach," Urios said on Twitter.
"I'm also thrilled to join such a prestigious club," he added.
The former hooker, who guided Castres to the 2018 Top 14 title, has signed a deal at Clermont until 2025, with an optional extra year.
"After fruitful internal and external discussions over the recent days, we have unanimously agreed the arrival of Christophe Urios at Clermont is the right choice," club president Jean-Michel Guillon said in a statement.
"His vision for the gameplan and the club correspond totally to what we're expecting," he added.
Urios' first game in charge will be January 28's Top 14 trip to Lyon with defence coach Jared Payne taking temporary control for this weekend's Champions Cup game at the Stormers.
The three-time Champions Cup runners up need at least a point in Cape Town to keep their hopes of a last 16 place alive.
Urios, who owns a vineyard and is well-known in France for his entertaining media outbursts, will then welcome former club Castres on February 4 before returning to Bordeaux-Begles for the first time two weeks later.