The Championship outfit are flying in the division having stormed to a 12-point lead at the summit, and now they are boosting their squad further.
Mir, who can play through the middle or on either side of a front three, has signed a four-and-a-half-year deal at Molineux.
The 20-year-old has been at Valencia since 2015, but has struggled to break into the first team and did not make a single appearance for the Spanish outfit this season.
After the transfer to Wolves was confirmed, Mir tweeted: "I would like to thank Valencia, the fans and the employees that form part of this great club for the opportunity they have given me to grow both personally and professionally.
"For six seasons I have lived with great professionals and shared unique moments in this wonderful city that is Valencia. I leave to face new challenges with the illusion that brings a new project where to continue learning and improving day by day.
"I sincerely wish much success and achievements to Valencia CF. Rafa Mir."
Mir has become Wolves' first signing of the January window.