The transfer fee was not disclosed but local media said Palace paid an initial 9.5 million pounds for the 28-year-old.
"This is the right time to move because I needed a new challenge. I have good memories of West Ham but I need to come here and give my best because I like the Crystal Palace project," Kouyate told the club's website.
Palace, who play Toulouse in a friendly on Saturday, open their new Premier League campaign at Fulham on Aug. 11.
($1 = 0.7624 pounds)
(Reporting by Aditi Prakash in Bengaluru; Editing by Peter Rutherford)
Share
