Opened 17 years ago, the eatery — whose entryway is lit with 7,000 marquee light bulbs like a Broadway theater — was slated to serve its last Big Mac on Tuesday, company officials confirmed.

A spokesman for the Oak Brook, Ill.-based company called the restaurant’s closure “a difficult decision,” although he insisted it wasn’t related to the coronavirus pandemic, which has devastated tourist haunts like Times Square for months.

“McDonald’s reviews its restaurant portfolio on a regular basis to make the best decisions for our business moving forward,” a spokesman told The Post in a statement.

The fast-food chain used the 17,500-square-foot burger mecca to test new menu items and to tout its financial results to Wall Street analysts, according to its first operator, Irwin Kruger.

“We launched national programs at that store like the salad program with Paul Newman dressing, World Children’s Day and [free] WiFi,” Kruger said. “That store was in the McDonald’s annual report.”

In 2003, anchorwoman Diane Sawyer worked behind the counter for a day for a news story on ABC’s “Good Morning America.”

But its flagship status ended last year when the largest restaurant company in the world opened an ultra-modern, all-glass eatery a few blocks away at 1530 Broadway.

Located in a former Toys R Us store, the new McDonald’s features 18 self-ordering kiosks — and just five cashiers — as well as upholstered banquettes and table service.

Management has even considered renting the fancy new flagship out for private events, including as a destination for New Year’s Eve because of its bird’s-eye view of the ball-dropping in Times Square, sources said.

“We look forward to continuing to serve our customers at the flagship McDonald’s on 45th Street and Broadway and in the neighboring communities,” the spokesman said.