Aina signed for the Serie A side on a season-long loan deal last summer – a deal which included the option to make the move permanent for a fee of £8.7m.
With the Nigeria international enjoying an impressive campaign in Italy - making 30 Serie A appearances – Torino claimed on Tuesday night they had exercised the option to sign the 22-year-old.
Chelsea have now confirmed his departure. "Everyone at Chelsea Football Club would like to thank Ola for his services and we wish him the best of luck for the next stage in his career," a statement read.
With Chelsea facing the possibility of a transfer ban, Aina’s departure is likely to strengthen Reece James’ chances of being part of the Blues’ senior squad for the 2019-20 season.
The 20-year-old is expected to miss the start of the season however after suffering ankle ligament damage while on international duty with England Under-20s.
