Millionaire businessman Willie Wilson offered Thursday to donate 10,000 medical masks and 1,000 more advanced “N-95” masks to the Chicago Police and Fire Departments to protect first-responders on the front lines of the city’s war against the coronavirus.

A former mayoral challenger whose endorsement helped Lori Lightfoot trounce Toni Preckwinkle, Wilson has spent a lifetime of charitable giving.

He has famously paid peoples’ property tax bills to prevent them from losing their homes. He has reached into his pocket to give cash to homeless and hungry people on the street.

On Thursday, he offered to put the medical supply business that is a major source of his personal fortune to work for a Chicago Fire Department that already has seen a paramedic and an assistant deputy chief paramedic testing positive for the coronavirus.

“In the last 30 days, I have sold to my customers probably about 10 million face masks. So when I got the news that people couldn’t get `em, I just said, ‘Let me just donate 10,000 to the first-responders,’” Wilson said Thursday.

“It’s the right thing to do. People are out here putting their lives at stake. And it could be me. They’ve got to protect themselves. I’m just giving it to them. I don’t want nothing from it. That’s my life. I give all the time.”

In addition to the medical masks, Wilson said he has another shipment of 5,000 N-95 masks coming in next week. After delivering 4,000 of those stronger masks to his customers, he’s planning to donate the rest to the Chicago Fire Department.

Wilson’s offer comes at a time when three first-responders — a paramedic, an assistant deputy chief paramedic and an unidentified police employee — already have tested positive for the coronavirus.

The police and fire cases are particularly troubling because of the threat that a more rampant spread could sideline a large group of first-responders just when they’re needed to handle additional cases.

“The fire commissioner says we would gladly accept the offer and appreciate his concern and contribution,” Fire Department spokesman Larry Langford wrote in a text message to the Sun-Times.

Rob Tebbens, political director for the Chicago Firefighters Union Local 2, was thrilled with what he called the “very generous offer.”

“My members want to be protected. My members are concerned about their safety and being prepared to do their job safely and having the right equipment to do their job safely. … There’s been claims that there’s been shortages of supplies and equipment. ... statements that have been made through the media,” Tebbens told the Sun-Times.

“I want to do everything we can to provide protection or additional protection or anything that provides them with the level of comfort or level of safety to effectively do their job and not become a part of the problem. We want to be part of the solution.”

Fraternal Order of Police President Kevin Graham could not be reached for comment.

N-95 masks have been in high demand during the pandemic because they filter out small particles from the air. They have long been used by construction workers, including painters, sanders and drywall contractors.

Earlier this week, Vice President Mike Pence appealed to construction companies to donate their inventory of N-95 masks to local hospitals and stop ordering new masks to ease a shortage of protective equipment at hospitals bracing for an avalanche of coronavirus patients.

“Those industrial masks that they use on construction sites are perfectly acceptable for health care workers to be protected from a respiratory disease,” Pence said during a White House briefing.

“We are asking construction companies that our president knows very well from his background [as a developer] — we’re asking them to donate their N-95 masks to their local hospitals and also forego making new orders.”

In a tweet, the U.S. Surgeon general pleaded with the American public to “STOP buying masks.”

“They are not effective in protecting the general public from contracting #Coronavirus. But, if health care providers can’t get them to care for sick patients, it puts them and our country at risk,” the tweet said.