The Citizens clocked up 98 points to win back-to-back Premier League titles, sealed with Sunday's 4-1 win over Brighton.
It was Kompany's fourth title win with the Citizens, and given the ongoing battle with runners-up Liverpool that went down to the final day, the Belgian thinks the 2018/19 title is the most memorable.
“It was the hardest and most satisfying Premier League title win ever," Kompany told City's official website.
“Liverpool were exceptional this year and I don't mean to rub it in – it is what it is – they didn't deserve to be second this year, but it only makes me that much more happy that we've been up against such a good team and when our backs were against the wall we kept finding the results.
“We won at the Etihad against Liverpool and I think that made the difference and once we got our noses in front, we were able to stay in front – I'm so happy for myself, the team and our fans."