The 24-year-old moves to the Portuguese club on a four-year contract after three years with Roma.
Jose Angel's deal contains a release clause of €30 million, with Roma in line to receive 50 per cent of any future transfer fee.
And the Gijon-born player is relishing the challenge of competing for one of Portugal's biggest clubs.
"It is a great joy to be here," Jose Angel told Porto's official website. "I think it [Porto] is a great club that is creating a good squad.
"It is important to have a good team and good players. Porto is making good signings.
"We will be fighting for important things. I have high expectations and cannot wait to start training and be 100 per cent.
"I will give the maximum to help the team. I hope that in the end everything goes well and we can all be happy."
