He will undergo a medical on Friday before signing a four-year contract.
"The Spanish international is due in Barcelona on Thursday evening and will have a medical on Friday morning.
"Villa will be officially unveiled as a Barca player. He will then make an appearance on the Nou Camp pitch.
"The stadium doors will be opened to the public."
He scored 21 league goals for third-place Valencia last season.
He is Spain's second all-time leading scorer behind Real Madrid legend Raul.