For about 40 seconds, "Polish airspace was breached by one of the cruise missiles fired in the night by the air forces... of the Russian Federation," the army wrote on social media platform X.
"The object flew through Polish airspace above the village of Oserdow (Lublin province) and stayed for 39 seconds," added the statement.
The army said that the missile was tracked by military radar throughout its flight.
"The Polish army is constantly monitoring the situation on Ukrainian territory and remains on permanent alert to ensure the security of Polish airspace," said the army.
Poland activated its air defence procedures during the incident, the operational command of the armed forces said in its statement.
A similar incident occurred on December 29, 2023, when a Russian missile penetrated Polish airspace for several minutes before returning to Ukraine.
In November 2022, two people were killed when a Ukrainian air-defence missile fell on the Polish village of Przewodow, close to the Ukrainian border.
Before the missile was identified as Ukrainian, fears were raised that NATO -- of which Poland is a member -- would be dragged into an escalation of the conflict with Russia if its collective defence provisions were triggered.