The 52-year-old announced on March 10 that he had tested positive for the virus, 12 days after Olympiacos eliminated Arsenal from the Europa League at the Emirates Stadium.
Arsenal manager Mikel Arteta similarly caught the virus after coming into contact with Marinakis after the game but the Spaniard has since made a full recovery.
Marinakis went into self-isolation after revealing his status but has now thanked the Greek healthcare system for his recovery and urged the general public to adhere to safety guidelines.
He wrote on Olympiacos' website: 'After completing two weeks, following the doctors' instructions, I also passed the second test (provided by the procedure), which turned out to be negative.
'I stayed home, read, communicated with friends and acquaintances, watched television for many hours, listened to music, spent many hours surfing the internet to see what was happening to the rest of the world, and realised once again how vulnerable our planet is.
'I feel the need to thank the doctors for their care and advice. Heroes in green and white t-shirts, who work nightly for their fellow people. The anonymous and well-known friends, each individually, for their unlimited love, their thousands of messages (even lyrics) and their selfless support.
'I also feel compelled, at this critical stage, to send a message that derives largely from the experience of my short-lived adventure. It is worth staying home to protect ourselves and our own people.
'Staying home raises a real shield on ourselves and stops the virus from invading. Staying home shields the whole, many, the public health and limits the spread of coronavirus. That is why there is no room for frivolity or personal decisions. Discipline and full cooperation with the State and the scientific community is essential.
'Once again I remembered what the great Greek writer Nikos Kazantzakis had said: "The stone, the iron, the steel cannot stand. Man can bear".
'Let's discipline and be sure we can afford it. We will come out even stronger on staff, but also nationally. Our health only goes beyond our control. Let us all be good, strong and strong.'
