Radja Nainggolan (born 4 May 1988) is a Belgian professional footballer who plays as a midfielder for Italian club Cagliari Calcio, on loan from Inter Milan.
Nicknamed Il Ninja, he spent his entire professional career in Italy, representing Piacenza, Cagliari, Roma and Inter Milan and making over 350 Serie A appearances. He was named four consecutive times in the Serie A Team of the Year.
A Belgium international for eight years, Nainggolan played 30 times for his country (scoring six goals) and represented it at Euro 2016.
In August 2019, Nainggolan returned to Cagliari on a season-long loan. He was named the league’s MVP for November, with two long-range goals and three assists in three matches to help his team reach fourth place.
Nainggolan returned to the Sardegna Arena on 31 December 2020, again on loan.