The almost 24 year-old has joined the English outfit according to sources across the continent in both Belgium and the Netherlands.
Although not the big number 9 which the Spurs are looking for, Chadli has a fairly good strike rate in terms of goals and assists with 18 and 12 to his name from 44 appearances in all competitions last season.
His arrival may have depended on current Tottenham players Mousa Dembele and Jan Vertonghan perhaps convincing Chadli to join.
Also linked with the likes of Liverpool and Swansea, Chadli's former team FC Twente were holding out for a bid of €9m but had to settle for a lesser fee because Chadli wanted the move there.