Conte was “attacked by an anti-vaxxer in Massa”, a small Tuscan city where he was attending an election rally, his opposition party the Five Star Movement wrote on Facebook.
News agency Ansa said the man struck Conte in the face, blaming him for the lockdown policies imposed during the pandemic and other measures. Police officers later took him away.
As well as his own party, Prime Minister Giorgia Meloni expressed her “solidarity” with Conte.
“Any form of violence must be condemned without hesitation,” Meloni said in a statement. “Dissent must be civil and respectful of people and political groups.”
Prime minister from June 2018 to February 2021, Conte was the head of government when the Covid-19 outbreak suddenly struck northern Italy in February 2020.
Italy was the first country outside China to suffer a major outbreak of Covid-19.
The virus has killed nearly 190,000 people in Italy to date, according to the health ministry.
Conte imposed stringent coronavirus restrictions in the early phase of the pandemic, including an economically crippling shutdown and the mandating of face masks in public.
His successor as prime minister, Mario Draghi, imposed a compulsory coronavirus health pass in September 2021 tied to the Covid-19 vaccine.
Conte’s early decisions during the breakout, including one not to impose “red zones” in two hard-hit areas, are the subject of an ongoing judicial inquiry.
Investigating magistrates suspect that Conte and his government underestimated the contagiousness of Covid-19 even though available data showed that cases were spreading rapidly.