The England Under 21 defender was jeered during the team's 2-0 win over Serbia in Nijmegen on Sunday.
Onuoha has moved to brush off the abuse, insisting his focus is on England's European Under 21 Championship semi-final with hosts Holland.
"To be honest, last night I was mostly thinking about the semi-final on Wednesday, so I was quite calm and happy," Onuoha told Sky Sports News.
While Onuoha was surprised by the racist taunts, the Manchester City youngster admits it was not a new experience.
He added: "I was a little surprised, it was a bit unfortunate. When I was younger I had it as well.
"It's something I've experienced before, so it's not really a massive thing to me."
Onuoha admits policing the issue of racism in football will be hard for Uefa to gain complete control over.
He added: "I think the job of Uefa is very difficult. They have got a lot of countries to govern over there and sometimes things like this can happen."