The midfielder has signed a new five-year contract that will keep him at the Etihad Stadium until 2027.
"Joining City in 2019 is the best decision I have made in my career," he said. "I have loved every second. The fans have been amazing with me, I feel totally supported by the Club and the manager pushes me every single day.
"I have improved so much as a player, and I want to thank Pep and all the backroom staff for their help. They are completely committed to helping me become the best player I can be, and I appreciate their hard work."
Rodri has won two Premier League titles since arriving from Atletico Madrid for £63 million.
He took over from Fernandinho as Pep Guardiola's preferred central midfielder but could face extra competition for his place next season after the £42m capture of Kalvin Phillips from Leeds United this summer.
"We have been very successful since I came here, which is something that makes me very proud," Rodri added. "But to be honest, that success has made me even more hungry for me. Once you start winning big titles, you don't want to stop.
"City, I feel, offers me the best chance of winning trophies and that's why I am so pleased to be staying here for longer."