In a message on Twitter, Balotelli wrote: "Finally the TRUTH :-)??...PIA ... Sweet child of mine !!! your Dad."
Italy striker Balotelli is no longer the partner of former on-and-off girlfriend and showgirl Raffaella Fico, who in July 2012 announced she was pregnant with his child.
Pia was born in December 2012 and Fico later accused Balotelli of distancing himself from his newborn baby daughter.
The 23-year-old player retorted several weeks later by threatening Fico with legal action if she continued making "further irresponsible comments".