The 18 year-old midfielder has signed a new deal to 2029.
Bernal has just recovered from a knee injury and was handed a new deal during his recovery last year.
Today, that contract was extended and improved, with Bernal stating: "Today is the most special and beautiful day of my life. It's what all of us players who have grown up like this strive for, and I hope to be here for many more years.
"The truth is that when I got injured and they told me Barça wanted to renew my contract, I felt like I was at rock bottom. It was a very tough day for me.
"They did something very special, something that meant a lot to me and my family. I owe everything to the club of my life."
He added, "There have been many people who have helped me a lot. Hansi (Flick) surprised me from the very beginning. When I was in the hospital, he came to visit me.
"He has been very close to me and attentive throughout the entire process."