The billionaire activist investor has entered into a lease for a 23,463-square-foot office in the new Milton Tower, becoming its first tenant. He now occupies about one-fifth of the building, including both the penthouse and the 12th floor, Milton Tower announced this week.

The Post first reported on Icahn’s plans to ditch his big city digs at 767 Fifth Ave. for sunny Florida last September. The 84-year-old investor, who grew up in Far Rockaway in Queens, moved into Milton Tower during the pandemic, its Executive Director Guy Gil told The Post.

“He is a very good negotiator,” Gil said of the deal with Icahn, the terms of which were not released. “We were going back and forth until the last dollar.”

In announcing plans to leave the city that never sleeps last year, Icahn, whose name adorns Mount Sinai’s School of Medicine and Icahn Stadium on Randall’s Island, cited the weather: “While I certainly don’t wish to retire, I’ve decided at this point in my life I’d like to enjoy a warmer climate and more casual pace year-around.”

Gil suggested the coronavirus could bring more neighbors for Icahn, saying that Northeast-based law firms, private investment firms and family offices have been calling him about leasing space in his 14-story tower.

“You will have only two to three people at one time in our elevators,” he said, compared to many more in 70-story Manhattan office towers.

Icahn has owned a home in Miami’s exclusive Indian Creek Village Island since 1997, where he lives alongside Spanish singer Julio Iglesias, former Miami Dolphins coach Don Shula and former Sears honcho Eddie Lampert.

He can now drive from his guarded island getaway to his office in under 1 mile.