The Spanish actor revealed the diagnosis on Instagram on Monday, which was also the day he saw in his 60th birthday.
Alongside a photo of himself as a child, he explained in Spanish: “I wanted to make it public that today, 10 August, I am forced to celebrate my 60th birthday in quarantine, after testing positive for the disease Covid-19, caused by the coronavirus.”
He went on to say that he is feeling “relatively well, just a bit more tired than usual”, and is confident that he will recover from the illness “as soon as possible”.
The Oscar-nominated star added that he plans to take advantage of his time in quarantine period by using it to “read, write, rest and make some plans to give meaning to my 60 years which I reach full with desire and excitement”.
He signed off the message: “A big hug to everyone, Antonio Banderas.”
During the coronavirus pandemic, a number of high-profile stars have spoken publicly about having tested positive for Covid-19.
Among the first to share their diagnoses were actors Tom Hanks and Rita Wilson, who contracted coronavirus in March while in Australia for work.
The Forrest Gump star claimed last month that as one of the first celebrities to become ill with coronavirus, he felt like a “canary in the coalmine”.
Fellow actor Idris Elba and his wife Sabrina Dhowre Elba also tested positive for Covid-19 in March, with the Luther star speaking more recently about the effect that contracting the disease so early in the pandemic had on his mental health.
This article originally appeared on HuffPost UK and has been updated.