Ronan Farrow’s ol’ blue eyes may say it all.

Farrow, long described as the only biological child of actress Mia Farrow and New York filmmaker Woody Allen, may actually be the son of Frank Sinatra, his mom acknowledged in a bombshell report Wednesday.

While Hollywood has whispered about the prospect for years, it was the first time that Mia publicly admitted the possibility.

Asked point-blank by Vanity Fair about Sinatra’s possible parentage of Ronan, Mia coyly replied: “Possibly.”

The “Rosemary’s Baby’’ actress was married to Ol’ Blue Eyes from 1966 to 1968 but continued to be his lover on and off afterward — including when she was involved with Allen. Sinatra died in 1998.

A DNA test has been never done to prove who Ronan’s father is.

Frank Sinatra and Mia Farrow cut their wedding cake. They were married for two years, but continued to see each other in the following decades.AP

But if the Chairman of the Board turned out to be Ronan’s dad, it would likely be welcome news to the 25-year-old wunderkind lawyer.

He has despised Allen ever since the nebbishy filmmaker ran off and married Ronan’s adopted sister, Soon-Yi Previn.

It also might be a slightly remarkable feat for Sinatra — who would have been around 78 when Ronan was conceived.

Still, it only takes one look at Ronan’s clear, gorgeous, blue eyes to see how much he takes after Sinatra physically, as opposed to the brown-eyed Allen.

Sinatra’s boots-are-made-for-walkin’ daughter, Nancy, stopped just short of calling Ronan a blood relative in her Vanity Fair interview — and openly gushed about his and Mia’s place in her family.

“[Ronan] is a big part of us, and we are blessed to have him in our lives,” Nancy Sinatra said.

As for Mia, “From the early days until now, [she and I] have been like sisters. My mother is also very fond of her. We are family and will always be.”

FilmMagic/Everett CollectionFilmMagic/Everett Collection

When Frank Sinatra died, Mia went to his funeral accompanied by Ronan, the magazine noted.

In the Vanity Fair piece, Ronan doesn’t talk about the daddy issue.

Instead, the former Rhodes scholar focuses on how he relished growing up with his quirky actress mom and adopted siblings.

“I am so proud of my family,” Ronan said.

“I grew up across the table from [brother] Moses, who has cerebral palsy, and next to my sister Quincy, born of a drug-addicted inner-city mother, and Minh, who is blind.

“I could never have understood what it means to grow up blind or with cerebral palsy. I saw problems and needs, so the next thing you think is: OK, what are you going to do about it?”

Woody Allen and Mia Farrow split in the 1990s.AP Photo/Christophe Ena

Mia and Allen split in the 1990s after she discovered nude photos he had taken of her adopted daughter, Soon-Yi, who was about 20 years old at the time and had at least partly grown up with Allen in the household.

In 2012, Ronan famously tweeted on Father’s Day: “Happy father’s day. Or as they call it in my family, happy brother-in-law’s day.”

Allen also had been accused at one point of molesting his and Mia’s adopted daughter, Dylan.

Mia recalled to the magazine how fearful she was of Allen after going public with the allegations in 1992.

Farrow said she was afraid that Allen, with his purported connections to shadowy Teamsters figures, could have her rubbed out. She said she relayed her concerns to someone she knew could protect her — the purportedly mob-connected Sinatra.

Sinatra wound up setting her up with a mafioso pal with whom she met in the back of a sedan on the Upper West Side at 72nd Street and Columbus Avenue.

“The Teamsters?” Sinatra’s fixer told Farrow. “Don’t worry about it. We own the Teamsters.”

Kristina Bumphrey/Getty ImagesKristina Bumphrey/Getty Images

“I remember babbling, ‘Thank you, thank you,’ ” Farrow said. “Off he went, and I did feel safer.”

In the wide-ranging article, Mia’s adopted daughter, Dylan, also broke her long silence about her allegations against Allen.

Dylan claims that when she was just 7, the four-time Oscar winner inappropriately touched her in the attic of her mother’s Connecticut home.

“There’s a lot I don’t remember, but what happened in the attic I remember. I remember what I was wearing and what I wasn’t wearing,” Dylan told Vanity Fair.

“The things making me uncomfortable were making me think I was a bad kid, because I didn’t want to do what my elder told me to do . . . [For all I knew] this was how fathers treated their daughters, this was normal interaction, and I was not normal for feeling uncomfortable about it,” she said.

Fletcher Previn has Photoshopped Woody Allen out of every family picture and edited him out of home movies.

Connecticut prosecutors declined to press charges against Allen — though the state’s attorney in Litchfield, Frank Maco, said he had “probable cause” to go after the movie maker.

Dylan, now 28, said that looking back, she blames herself for not insisting that Allen be prosecuted.

“I have never been asked to testify. If I could talk to the 7-year-old Dylan, I would tell her to be brave, to testify,” she said.

Dylan said that in the years since the alleged attack, Allen has reached out to her twice by e-mail.

She said she found it particularly creepy that he also mailed her a large manila envelope filled with pictures of them together.

The return address on the envelope didn’t list Allen’s name, so she was unsure who had sent it, and she opened it.

“I should have recognized the handwriting. I didn’t. It had a fake return name: Lehman,” Dylan said.
Woody had the gall to say he still wanted to be her dad, she said.

He wrote, “I thought you’d want some pictures of us, and I want you to know that I still think of you as my daughter, and my daughters think of you as their sister. Soon-Yi misses you,’ ” according to Dylan.

Getty Images/Everett CollectionGetty Images/Everett Collection

Dylan said she was disgusted and couldn’t believe Allen could still view her as his daughter.

“How do your daughters think of me as their sister? How does that work?” she said.

Mia’s brood has gone to great lengths to wipe Allen from their collective memory.

Computer whiz Fletcher Previn — Farrow’s biological son with conductor and former hubby André Previn — has Photoshopped Allen out of every family picture.

Fletcher has also edited Woody out of all their home movies.

“We can look at them and be reminded of the good and not be reminded of the bad,” he said.

Fletcher even blamed Woody for the 2008 death of his adopted sister, Lark Previn. She died on Christmas Day 2008 at age 35 of pneumonia.

Fletcher said Allen turned the family upside down when he ran off with Soon-Yi and sent Lark down a bad path.

“To my siblings and me, you thought of [Allen] as another dad. It can disrupt your foundation in the world. It resets the parameters of what is possible,” Fletcher said.

“There were casualties who were totally derailed. It had a different impact on everyone, but everyone had a reaction,” he said.

“I really do think he’s [Allen’s] got some blood on his hands.”