Carlos Vicens’ side beat Chelsea 3-2 in the final to win the trophy for the first time since 2008 having lost four of the previous five finals.
It was a fine performance from City, built on hard work without the ball and technical quality in possession.
And Guardiola, who has given four members of the side who played the final first-team debuts over the past 14 months, was impressed.
“I want to congratulate all the players, as well as Carlos and his staff,” Guardiola said.
“I thought their performance was outstanding. They showed so much courage and personality – not just in the final but throughout the competition.
“They worked so hard without the ball and when they attacked, they did it with creativity. I was so impressed.
“It is testament to the strength of our Academy right now. There are a lot of very good players coming through.
“Hopefully, they enjoy this achievement and continue to develop because some of them have fantastic futures ahead of them.
“The Academy teaches young players to play the game in the right way and we are seeing the benefit of that at every age group.”