Banderas, who is best known for his roles in Desperado and The Mask of Zorro, announced his diagnosis on social media and revealed that he was experiencing symptoms of fatigue.
The actor celebrated his girlfriend Nicole Kimpel's 40th birthday with friends a week and a half ago and shared photos of the party including a large cake on his Instagram page.
Spain is the worst-hit nation in Europe at the moment, with many of its neighbours including Italy, Germany and the UK, recommending against travelling there.
And Malaga is one of the Spanish regions that continues to be worst hit by coronavirus, recording more than 800 new cases a day last week and face masks are mandatory in public spaces indoors and outdoors.
Banderas reassured fans that he expected to make a full recovery in the near future.
The Madrid-born actor posted online: 'I feel relatively well, just a little more tired than usual'.
The news of his diagnosis comes just days after celebrating girlfriend Nicole Kimpel's 39th birthday in Malaga
Spain has already been hit with new travel restrictions in a blow to its tourism-reliant economy.
The country has so far seen 314,362 confirmed infections, with cases soaring over the past week and 28,503 deaths recorded.
On Friday the Health Ministry reported 4,507 new infections -- nearly 500 more than the day before.
The data, however, does not include information from the hardest-hit region of Aragon due to technical issues.
Banderas said he was 'confident that I will recover as soon as possible' from the 'infectious process that I suffer and that is affecting so many people around the planet'.
The actor added that he would be spending his time in isolation focusing on reading, writing and resting.
He skipped a charity gala which he was supposed to host on Sunday in Marbella on southern Spain's Costa del Sol, not far from his Malaga hometown.
He said he would 'continue making plans to begin to give meaning to my newly released 60 years to which I arrive loaded with desire and enthusiasm'.
Banderas has homes in Spain, the US, and near Surrey in England.
The actor's work with Pedro Almodovar made him a star in Spain, before pop star Madonna introduced him to Hollywood.
He carved an illustrious career spanning more than 100 movies, with huge blockbuster success including Philadelphia, Puss in Boots, and Pain and Glory.
Banderas previously suffered a heart attack in January 2017 and credited Nicole with saving his life after giving him aspirin when he started suffering symptoms.
He later underwent surgery to insert three stents in his arteries.
Banderas is the latest in a string of high-profile figures to test positive for the illness, including Tom Hanks, Idris Elba, Bryan Cranston and the singer Pink.
The Mediterranean country announced nearly 26,000 new infections in the last seven days, up from 16,000 the week before and fewer than 2,000 in late June.
Catalonia alone saw more than 5,000 cases in the space of a week, while the nearby region of Aragon had the country's highest infection rate per 100,000 people.
Despite Spain's increase in cases, only 46 virus patients were admitted to intensive care in the week up to last Friday, compared to more than 20,000 people who tested positive for the virus.
The death toll has generally remained in single figures despite the recent increase, with only 16 fatalities in the week to Thursday.
The country has a series of strict rules in place in a bid to stem an uptick in infections.
These include keeping a social distance of 1.5 metres, the mandatory wearing of face masks in public spaces and tracking and tracing methods.
Spanish police today broke up a 'coronavirus party' where guests were allegedly trying to spread the disease on purpose - as the country suffers a sharp rebound in cases with infections rising across Europe.
More than 60 people were found camping on an out-of-bounds Tenerife beach in what police called a 'get-together on the beach to spread Covid-19', apparently in the hope of developing immunity.
Civil Guard officers swooped to shut down the gathering with youngsters forced to dismantle their tents, but officials say the party was a 'very serious threat'.
Los Patos beach on Tenerife, where the alleged 'coronavirus party' took place, is traditionally a well-known nudist beach on the Canary Islands which have been lobbying for an exemption from Britain's quarantine rules.
As European countries struggle to manage spikes in coronavirus cases, concern is mounting about a 'second wave' of uncoordinated border restrictions within Europe that threatens the free movement of goods and people - a foundation that the world's biggest trading bloc is built on.
Despite repeated warnings about the dangers of unannounced checks, some countries have imposed new restrictions, or demanded that travelers quarantine.
This is recalling the panic border closures after Europe's first outbreak emerged in Italy in February, blocking traffic and medical equipment.
Beyond the economic impact of uncoordinated measures, experts fear that countries are becoming so used to lowering the gates at their frontiers as they see fit that the future of Europe's ID-check free travel zone known as the Schengen area is in real peril.
In a letter to national governments, the European Commission warns that 'while we must ensure that the EU is ready for possible resurgences of COVID-19 cases ... we should at the same time avoid a second wave of uncoordinated actions at the internal borders of the EU.'
'The re-establishment of ineffective restrictions and internal border controls must be avoided.
'Rather, the response should be to have targeted, proportionate and coordinated measures, informed by scientific evidence,' the letter, sent to the 27 EU member countries and Britain, said.