Marseille said on Wednesday Bruno Genesio has replaced Habib Beye as coach of the Ligue 1 club.
Former Aston Villa defender Beye left the position on Tuesday having failed to secure Champions League football in his four months in charge on the Mediterranean coast.
Genesio, 59, left Lille at the end of last season having guided the northern outfit to the elite European competition.
The managerial debate at Marseille had been put on ice earlier in June after the club were hit with sanctions by UEFA for failing to meet the European football governing body's break-even targets.
"This appointment is part of the new sporting cycle undertaken by the club in order to pursue its development and sustainably strengthen its competitiveness at the highest level," Marseille said.
"With a wealth of experience gained at both domestic and European level, Bruno Genesio has established himself over the years as one of the most highly regarded French coaches," the 1993 Champions League winners added.
Former midfielder Genesio has also had spells at the helm of Lyon, Rennes and Beijing Guoan in China.
During his time at the Bretons, Genesio was named 2021-2022 French coach of the season having guided the outfit to fourth in the table and the Europa League last 16.
"I chose to join Olympique de Marseille because I was drawn in by the challenge that was presented to me," Genesio said.
"OM is a unique club, with an exceptional history, a strong identity and supporters whose passion is recognised far beyond its borders," he added.
Marseille finished fifth last season and begin the new Ligue 1 campaign on the weekend of August 21-23 at home to Strasbourg.