Joan Garcia, 24, had originally joined Barca's local rivals as a teenager and kept eight clean sheets in 38 appearances last season.

He becomes the Catalans' first summer signing after Hansi Flick's side won four trophies last season including La Liga.

"He has just completed a fantastic campaign in La Liga, playing a key role in Espanyol's survival," Barca said.

"His outstanding performances, combined with his exceptional potential at just 24 years old, has made him a target for many top clubs around the world, Barca included," the 28-time La Liga champions added.

On Tuesday, Garcia said his goodbyes to Espanyol fans in a video on social media.

"I know this decision will not be easy for everyone to understand," Garcia said.

"I don't ask you to do so.

"But I want you to know that it has been a very well thought out decision, considering not only my career but also the best for the club, my family, and myself," he added.

Garcia is set to compete with Germany's Marc-Andre Ter Stegen, Poland's Wojciech Szczesny and Spaniard Inaki Pena for Barca's number one shirt next season.