Niels Nkounkou will join Saint-Étienne for an undisclosed fee after the French club took up the option to sign the left-back on a permanent transfer.
Nkounkou, who moved to Everton in July 2020 following the end of his contract at Marseille, has spent the second half of the 2022/23 season on loan at Saint-Étienne, making 19 appearances and scoring six goals for the Ligue 2 club.
The 22-year-old Frenchman initially moved to Cardiff City for the first half of the campaign, having been on loan with Belgian side Standard Liege in 2021/22.
Nkounkou, who will sign for Saint-Étienne on 1 July once his loan period ends on 30 June, made seven appearances for Everton, having made his debut against Salford City in the Carabao Cup in September 2020.
Everyone at Everton thanks Niels for his service and wishes him all the best for the future.