Dembele is a key member of the Celtic squad that is set to win another Scottish league title. However, the French star wants to pursue his career in one of Europe's bigger leagues.
Villarreal could offer him that opportunity in the summer.
A report in the Daily Star suggests that the Spanish club nicknamed the "Yellow Submarine" are willing to pay as much as £15 million for his signature.
The 21-year-old is seen as one of the top striking prospects in Europe.