As Blazej Spychalski announced on Saturday, Polish President Andrzej Duda was tested on Friday and found to be positive.
He is joining a handful of world leaders, including US President Donald Trump and UK PM Boris Johnson, who has caught the virus.
Poland is facing a surge in the coronavirus pandemic, with more than 13,600 new cases recorded daily on Friday.
The nation has now entered a "red zone" lockdown nationwide that involves the partial closure of primary schools and restaurants.
While it is unclear when Mr. Duda contracted the virus, he attended an event on Monday in Tallinn, where he met with Rumen Radev, the Bulgarian President, who later went into quarantine.
"The president was tested for coronavirus yesterday", Mr. Spychalski said on Twitter on Saturday.
"The result turned out to be positive. The president is all right. We are in constant contact with the medical services that are relevant."
Poland's new education minister tested positive earlier this October as well.