Tom Landry died a … Giants fan!

Yes, according to the widow of the legendary Cowboys coach who says in a new book that Landry was so disgusted by Jerry Jones’ treatment of him during and after his 1989 firing that he spent the rest of his life rooting for Big Blue instead of America’s Team.

According to “The Last Cowboy: A Life of Tom Landry,” by Long Island author Mark Ribowsky, Alicia Landry also claims that Jones took away the Landry family’s suite at since-demolished Texas Stadium and barred Landry’s son, Tom Jr., without explanation from continuing to buy Cowboys season tickets.

Jones’ behavior prompted Tom Landry to renew his love of the Giants — where he had served as defensive coordinator from 1954 until taking over the expansion Cowboys in 1960 — until his death in 2000.

Landry’s widow said she still cheers on the Cowboys’ NFC East rivals to this day.

“The Giants are still like family,” Alicia Landry said in a December 2011 interview, according to the book. “I still have dinner with Ann Mara [Wellington Mara’s widow] when she comes in. …The Giants never stopped being our family.”

Jones famously fired Landry after 29 seasons as coach on a golf course in Austin, Texas, shortly after purchasing the Cowboys from the late Bum Bright in February 1989.

The Cowboys had gone 3-13 in the final year of Landry’s Hall of Fame career and missed the playoffs three consecutive seasons, but Landry’s widow says the coach never got over how poorly his dismissal was handled.

Landry went to Texas Stadium just three times after being axed, but only to attend tributes to himself or former players and not as a Cowboys fan.

“He really didn’t have any dog in the hunt,” Alicia Landry said, according to the book. “A football game is good if you care who wins. He didn’t. It wasn’t his job anymore.

“That’s why I watch Giants games. I want ‘em to win so I get involved in watching their games, as did [Tom Landry]. We loved the Maras the way we loved the [family of original Cowboys owner Clint Murchison]. After [the firing by Jones], well … it wasn’t the same.”

Alicia Landry claims that, shortly after the coach was dismissed, Jones confiscated the luxury suite the Landry family had been given free by Murchison when Texas Stadium was constructed in 1971.

Shortly afterward, the book says, Landry’s eldest son was informed he would no longer be able to buy the six season tickets at the 50-yard line that he had purchased every year the stadium was open.

“It was a very nice box too, right next to the press box,” she said, according to the book. “I guess they really needed it. Whatever the reason, we didn’t have the seats.”

The Cowboys released a statement:

“Our ownership’s relationship with the Landry family has developed and grown through the years with many shared experiences celebrating the life and career of Tom Landry and his teams. There is a tremendous level of respect and admiration that the Jones family, and everyone in the organization, has for Coach Landry, his family and his legacy.”

Landry’s widow said her relationship with Jones is still so icy that she has never been to lavish AT&T Stadium in Arlington, Texas, for a football game since Jones opened it in 2009.

“I don’t know him at all,” she reportedly said of Jones. “I really don’t. I know what he looks like. I’ve seen him a few times and we say hello to each other in a friendly way. But I don’t know him.”

There is a statue of Tom Landry outside the Cowboys’ new stadium, and several roads in the Dallas-Fort Worth area have been named after the most beloved sports figure in the region’s history.

But Alicia Landry said her late husband would not have wanted the new stadium named after him simply because of Jones.

“The bond wasn’t there anymore,” she said. “I certainly don’t care about it. … It’s not the same Dallas Cowboys. I didn’t really want the new stadium to be named after Tommy anyway.

“They call it ‘Jerry’s World,’ which is more about what it is than anything Tom Landry was.”