The unveiling comes 10 years to the day since the striker's iconic stoppage-time winner against QPR saw the club clinch the Premier League title from the clutches of rivals Manchester United and ended a 44-year wait to become league champions.
Aguero's statue was created by award-winning sculptor Andy Scott and he joins fellow former City players Vincent Kompany and David Silva in being immortalised outside of the stadium.
The Argentine marksman, who retired from the game last year, told Sky Sports: "It's fantastic! I'm very happy for it, it's special.
"That moment changed my life, the club, everything. The best moment in my life. It will always be in my heart.
"We don't know what would have happened if we lost the Premier League that year. That year changed everything because the next years we started winning more titles."
Aguero's goal marked Manchester City's arrival as a major force in English football and he went to become a key player in the club's success before his exit last year.
He said: "Truthfully, it is a very beautiful thing for me, to see myself 10 years ago is very moving.
"In those 10 years, I was able to win a lot of trophies and was able to help the club become one of the most important in the world.
"I am very grateful to the club for making this statue in recognition of my football career in Manchester. It is something very special."