Nottingham Forest have signed the Ivory Coast defender Ousmane Diomande from Sporting on a four-year contract, with the option of a further year. The deal is a fixed fee of around £34.3m (€40m), agreed after weeks of negotiation.
Head coach Oliver Glasner drove Forest's interest in the 22-year-old, having previously tried to sign him during his time in charge of Crystal Palace. Diomande began his career in Denmark with FC Midtjylland before joining Sporting in January 2023, going on to make 132 appearances and score seven goals, and won the Primeira Liga twice as the club reached the Champions League knockout stages, starting both legs of a quarter-final defeat by Arsenal, and completed a domestic double in the 2024/25 season. He has 15 caps for Ivory Coast, with whom he won the 2023 Africa Cup of Nations for the first time in eight years, and played the full 90 minutes of their World Cup group win over Curaçao this summer.
"I am very happy to be here. It is a historic club, and it motivates me to join such a club," Diomande said. "I believe we can achieve very good things this season and I am looking forward to meeting the players and head coach. I will give my best." Forest's chief football officer, George Syrianos, said: "We have been very clear on the profile of player we want to add to the squad, so we are excited to welcome Ousmane to the club." He added: "Ousmane is a powerful, commanding defender, and arrives here with a winning mentality." Syrianos also pointed to his pedigree: "He has fantastic experience for a defender of his age. Playing a crucial role in title winning teams and going into the latter stages of the Champions League puts him in a great position to integrate well here at Forest."
Diomande, who is not related to Real Madrid's summer signing Yan Diomande despite sharing a surname and nationality, becomes Forest's third permanent signing of the window, after the Portugal midfielder Gustavo Sá and the Austria midfielder Xaver Schlager, the latter arriving on a free transfer from RB Leipzig. Glasner continues to rebuild a squad that reached the Europa League semi-finals and avoided relegation last season, after selling Elliot Anderson to Manchester City.