On 31 January 2020, Onana joined
Lille from
Leixões. Onana made his professional debut with Lille in a 2–1
Ligue 1 loss to
Marseille on 16 February 2020. In August 2020, he joined Belgian club
Mouscron along with some Lille players on loan, where he received a red card in a
Division A match defeat to
Kortrijk on 13 September. On 30 August 2021, Onana moved to Ligue 1 club
Bordeaux on a five-year contract. On 1 September 2022, he signed for his former club Lille's rivals
Lens on a five-year contract. He made his first appearance with Lens on 4 September 2022 against
Reims. On 21 July 2023 Onana moved to
Süper Lig club
Beşiktaş. On 11 December 2023, it was officially announced that Onana has been excluded from the Beşiktaş squad along with
Vincent Aboubakar,
Valentin Rosier,
Rachid Ghezzal and
Eric Bailly due to poor performance and incompatibility within the team. On 30 January 2025, Beşiktaş sent Onana on loan to
Serie A club
Genoa until the end of the
season, with an option to make the move permanent. On 1 September 2025, Onana returned to Genoa on loan with a conditional obligation to buy. ==International career==