The former Premier League outfit, Swansea, could only manage a 15th spot in the Championship last season, with 61 points from 46 games.
Guehi, a 21-year-old centre-back, joins Palace after a season-and-a-half on loan at Championship side Swansea City.
Rio Ferdinand’s late goal helped Manchester United beat Swansea City 2-1 as the famous old stadium also bid farewell to another legend - Paul Scholes.
The former German goalkeeper has apologized for his actions since the story came into the public eye but it could not save his job.
After being relegated in the previous Premier League campaign, Norwich City have secured their fourth promotion in a decade.