The young Plymouth talent stunned the field in Eindhoven in Holland, winning the 10-metre platform title.
Daley qualified for the Beijing Olympics with his victory, admitting afterwards he could not quite fathom the speed of his success.
"If somebody had told me at Christmas I would be a European champion at Easter my answer would have been 'go away'," he said.
"It was a perfect competition for me. If it seems as if I was without nerves I can tell you I have nerves and they were quite tense."
The teen star became the second-youngest male Olympian in British history at the 2008 games.
Daley finished eighth in the 2008 Olympics at the 10m discipline – but would go on to win bronze at the 2012 Games in London.
He also claimed gold at the World Championships in 2009, and again in 2017, to add to further European titles in 2012 and 2016.
Daley also claimed bronze in the 10m synchro alongside Daniel Goodfellow at Rio 2016.