Italy international Roberto Soriano has agreed a five-year contract with Villarreal, ending his seven-year association with Sampdoria.
Soriano joined Samp from Bayern Munich in 2009, making his debut for the Genoese club in 2011 following a loan spell at Empoli.
The 25-year-old midfielder has been capped by Italy eight times but missed out on a place in Antonio Conte's squad for Euro 2016.
An official club statement read: "Sampdoria announces it has sold the rights to Roberto Soriano outright to Villarreal.
"President Massimo Ferrero and the whole club would like to thank Roberto for the commitment and professionalism he always showed when wearing the Sampdoria shirt and wish him luck and glory for the rest of his career."
In a message to the Samp fans, Soriano wrote: "I arrived in Genoa as a boy, a young player looking for his way.
"I leave Genoa a man and a professional: the credit for which is all to Samp and its supporters who have accompanied me in these years with care and affection."
Soriano will be presented to the Villarreal fans and media on Wednesday evening.
The Italy international joins the likes of Denis Cheryshev and Alexandre Pato in moving to El Madrigal ahead of the 2016-17 season.