The mega-money deal for the 18-year-old forward is understood to have been completed and should be announced later today.
It is a seen as a huge coup by Molineux chiefs, with the highly-rated teenager having previously been compared to Cristiano Ronaldo.
Silva is costing more than last season's top scorer Raul Jimenez, who was snapped up permanently from Benfica for £32m last summer.
He is the youngest scorer and appearance-maker in Porto history and helped them win the Primeira Liga and the Taca de Portugal last season, scoring three goals in 18 appearances.
Sporting Lisbon legend Manuel Fernandes, in 2018, said about Silva: “When Ronaldo was 17, he played as a centre forward for Sporting's youth teams.
"I saw him doing things that I'm now seeing a boy from Porto do, Fabio Silva. He will be a hell of a player. In a short time, he will be an extraordinary striker.”