"I'm extremely happy and I can't wait to join Paris Saint-Germain," Berchiche said. "It will be an honour to wear the jersey of this club, which has become one of the best and most admired in Europe.
"I'm convinced that I will find here the perfect environment in which to reach my potential - by making progress and winning titles. Everyone knows how ambitious Paris Saint-Germain is in Europe. In conjunction with the staff and players, I will do all I can to help fly the Paris Saint-Germain flag as high as possible."
Berchiche appeared 35 times in La Liga last season, scoring three goals and crafting two assists, enhancing his reputation as a tough full-back, but one who's proficient with his deliveries off the flank.