The 20-year-old is poised to sign a four-year contract for a transfer worth around £1.5million, the Express & Star understands.
The 6ft 2in Spanish youngster has been in Valencia's youth setup for the past six years and has made two senior appearances.
However he has been prolific for the club's reserve team, netting 15 goals in 19 matches for Valencia Mestalla in the Spanish third tier.
It had been suggested that Real Madrid were looking at signing Mir, but Wolves have swooped to land their first signing of the window.
It's believed Wolves were looking at possibly bringing in another forward and a right wing back during the next few weeks.
There are set to be more outgoings than incomings with Michal Zyro, Ben Marshall and Prince Oniangue likely to be shipped out.