The striker has been linked with a move away from the newly-crowned Premier League champions, Mancini admitting after his sending off in last month's defeat at Arsenal he would "probably" sell him.
Reports in Italy have suggested Balotelli could head to AC Milan this summer in a swap deal which would bring Zlatan Ibrahimovic to the Etihad, but Mancini told Gazzetta dello Sport: "Mario has been very clear and I reiterate: Balotelli will remain at Manchester 101%."
The Italian added: "Ibra is a great player but I don't think Milan want to sell him.
"I'm going to be honest, we haven't looked at the market yet. In the last five weeks our only focus has been the league."
Balotelli, who set up Sergio Aguero for the 94th-minute winner against QPR which earned City their first league title since 1968 on Sunday, has been included in Italy's preliminary squad for Euro 2012.
"I am confident he will have a great European championship," Mancini said. "I hope Mario will be the leader of the national team because he is the best Italian striker.
"He just needs to make his brain work. That is his only problem."
Balotelli joined City from Inter Milan in August 2010 and is under contract until June 2015.