Immobile, who is 30, had the best league scoring season of his career, hitting 36 goals, 14 of them penalties, to lift Lazio to fourth place in Serie A.
“With this choice, Immobile has opted for Lazio for life,” said Stefano De Martino, Lazio’s communications director on the club’s website.
Immobile had previously finished top scorer in Serie A in 2013-14 with Torino and 2017-18 with Lazio, when he tied for first with Mauro Icardi.
He was previously under contract until 2023.
For Immobile “it’s a professional, sentimental and family choice” said Lazio adding that they intends “to consolidate what was done last season before further improving the squad.”