The suspect is allegedly responsible for setting at least 12 fires since September, Italy's ANSA news agency reported.
He was taken into custody Thursday in Tuscany after being caught setting fire to brush. He is currently under house arrest, the report said.
Meanwhile, another fire erupted Friday in Nuoro, central Sardinia, forcing a local university to evacuate.
The fires have been burning thousands of acres of forests in Viterbo, Lazio, Liguria, and Sardinia.
The Pollino National Park in southern Italy is at risk of catching fire, officials said.
"The whole park is surrounded by fires. What's happening tells us this will not be a calm year," said Domenico Pappaterra, the park's president.
The fires are believed to have been started deliberately, the report said.