Villar, 21, arrives from Spanish side Elche CF for an initial fee of €4 million.
Various performance-related clauses, worth up to a maximum of €1m, are also included in the deal.
The central midfielder has signed a four-and-a-half year contract with the Giallorossi that runs until 30 June 2024.
“I’m joining a great club and I couldn’t be happier,” Villar said.
“It’s a great challenge for me, I can’t wait to show what I am capable of.”
Villar came through the youth system at Elche, before joining Valencia during his teenage years.
Ahead of the 2018-19 season he returned to his boyhood club, establishing himself as a key player for the La Liga 2 side and earning his first call-up for Spain’s Under-21 national team.
“We are really pleased to be able to bring Gonzalo to Trigoria,” said club chief executive Guido Fienga.
“Gonzalo is exactly the sort of central midfielder we have been looking to add to our squad: he’s young, he’s talented and has great ambition to succeed.”
Villar will wear the No. 14 shirt at Roma.
I confirm that I have read the privacy policy.
© 2018-2024 Soccer S.r.l. – EU VAT IT09305501000 - all rights reserved. The AS Roma names, logos and artwork are registered or unregistered trademarks of Soccer S.r.l. All other trademarks may be the property of their respective holders.