The 18-year-old defender has enjoyed rapid development this season which he admits has surprised even himself.
"At the start of the season I was a substitute in the reserves team," he told the official City website. "It is just 6 months since I signed my first professional contract so if things keep progressing like this I will not be complaining.
"I have played 6 games in succession at right back now and feel I have been steadily improving," added Onuoha, who also made his debut for the England U20's in February, scoring 5 minutes into a 2-0 win.
"If I can keep developing the way I have then maybe I could make the position my own, who knows."
Richard Dunne agreed a contract extension today and Onuoha's new deal is a further indication that the players expect Stuart Pearce to remain in charge.
"The manager's position in these contract negotiations was very important as he is the one who has given me a chance," continued Onuoha.
"I feel he has a lot of confidence in me and believe it would have been a mistake not to have signed the contract. I thought when I signed my first professional contract, that was it, so this new deal was totally unexpected.
"As a City fan it is fabulous to think that I will be here for another 3-and-a-half years. Of course, that's if the fans still like me!"