The 25-year-old has penned a five-year contract, keeping him at the club until 2028.
The deal for the talented midfielder is understood to be worth €30 million plus add-ons.
Sangare’s signing represents a significant coup for Forest, who barely managed to maintain their top-flight status last season.
The Ivorian joined PSV in 2020 and hit the ground running at the Philips Stadion, making 140 appearances in all competitions over the next four years.
He featured in 29 matches in the Eredivisie last term, averaging an impressive 2.3 tackles, 0.8 interceptions and 1.6 clearances per game.
He also made six goal contributions to help the Red and Whites secure a second-place finish.
Sangare’s performances saw him linked with Paris Saint-Germain, Bayern Munich and Liverpool.
However, Forest beat off competition from the European heavyweights to secure the services of the 25-year-old.
Forest have had an excellent 2023 summer transfer window. They initially wrapped up deals for Chris Wood, Ola Aina and Anthony Elanga.
Goalkeeper Matt Turner and defender Murillo were next to arrive before a flurry of activity on deadline day.
Nicolas Dominguez, Callum Hudson-Odoi, Odysseas Vlachodimos, and Andrew Omobamidele joined on Friday, while Nuno Tavares and Divock Origi also arrived on loan.
But it was Sangare’s move that was the most surprising of all considering the interest in the midfielder from some of Europe’s clubs.
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