The 13-year-old, from Asby, near Frizington, did enough in the final round in Sweden, to win the same event three-time Formula 1 world champion Lewis Hamilton pipped Nico Rosberg to 17 years ago.
Jonny finished second, 150 yards ahead of Londoner Harry Thompson after 21 exhausting laps. Despite being hit with a penalty which dropped him to fourth, the result secured him the title.
Dad Justin said: “Winning the European Championship is a fantastic achievement and it will open a few doors.
"We’ve all enjoyed our share of success, but nothing on the same scale as Jonny’s achievement, so I’m an extremely proud dad right now.”
Jonny is a pupil at Cockermouth School.
Meanwhile, Jonny’s six-year-old cousin Jorge is also competing in the sport, as part of the Bambino Kart Club.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here