Spurs have reached an agreement for Chadli with FC Twente and he will complete a move to England once personal terms have been agreed and a medical completed.
The Belgium international will become Spurs' second signing of the summer once he makes his way to White Hart Lane, with Paulinho having already been added to the ranks.
Villas-Boas was expected to be busy during the current window, after seeing Tottenham fall agonisingly short in a push for a top-four finish last season, and the Portuguese coach has revealed that he is hoping to add further competition for places.
"We will continue to do our market and we have not stopped yet, for sure," he said.
A striker is reported to be top of Villas-Boas' wish list, with Spurs seemingly well stocked for creativity in midfield.
Chadli has added to the wealth of playmaking talent, with his versatility in the final third making him a shrewd addition.
Villas-Boas said of the 23-year-old winger: "Chadli's a player we've been following for quite some time and we managed to strike a deal in the last few days.
"He's a player who is extremely versatile and can play in several positions up front. He played with tremendous success on the left for Twente as a winger and as an attacker for Belgium. We look forward to having him on board with us."