Bruno Genesio was officially named Rennes' new coach by the Ligue 1 club on Thursday, a day after news of the former Lyon manager's appointment was leaked.
In a statement Rennes said that Genesio, 54, had signed a deal until June 2023 with the Brittany-based team as they try to pull themselves out of a slump in which they have lost five games in a row.
Frenchman Genesio returns to his home country where he previously spent three and a half years in charge of Lyon before departing in 2019.
He then had a stint in China with Beijing Guoan but he left at the start of this year when his contract was not renewed.
Previous coach Julien Stephan quit Rennes on Monday after a run of just one win in 10 matches. They sit 10th in Ligue 1 after Wednesday's 1-0 defeat at Lyon.
Stephan had been in charge since December 2018 and led the team to victory in the French Cup in 2019, their first major trophy since 1971.
Under Stephan Rennes then finished a best-ever third in the last Ligue 1 season, which was curtailed due to the coronavirus pandemic.
That saw them qualify for the Champions League for the first time in their history, but they finished bottom with just one point in a group also containing Chelsea, Sevilla and Krasnodar of Russia.