Richard Ferrand replaces Francois de Rugy as president of the National Assembly. Macron named Rugy as his environment minister last week.
The 56-year-old Ferrand comfortably won Wednesday’s ballot by lawmakers, despite facing a judicial investigation for alleged conflict of interest.
His 254 votes were more than the four other candidates combined.
The judicial probe, formally opened in January, followed media reports about Ferrand’s past business practices as head of a Brittany insurance company.
Ferrand denies doing anything illegal.