Balotelli has been linked with AC Milan.
"Mario has been very clear and I reiterate: Balotelli will remain at Manchester 101%," said Mancini.
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 the 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."