Jeffrey Slonim in 2014.

Jeffrey Slonim, longtime event and red carpet reporter, has died at the age of 56.

A known presence at soirées in Manhattan, Los Angeles and the Hamptons, Slonim had over the years contributed long-running, celebrity-centric columns to Allure and The New York Post, and most recently had written for Town & Country and Gotham magazines.

He is survived by wife Fiona Moore; children Finbarr, 18, and Declan, 15; sisters Anne and Amy, and artist brother Hunt Slonem.

The cause of death was suicide. Slonim died Oct. 13 at the New York Presbyterian/Weill Cornell Medical Center in New York, according to a spokesperson with the New York Medical Examiner’s office. His death followed what appeared to be a deliberate fall on Thursday from Lincoln Center’s Illumination Lawn.

Slonim — a graduate of Yale University — had also contributed to People, Blackbook, Condé Nast Traveler, Architectural Digest and the New York Observer, amongst other titles. From 2007 to 2009, he served as society editor of Interview magazine, later becoming a contributing editor until 2012. He held a “Snaps” column in the Post from 2001 to 2006. From 1995 onward, he served as editor at large to Hamptons Magazine.

Slonim’s family declined to comment.

“Private Eye,” Slonim’s column at Allure, appeared on the magazine’s back page from the publication’s 1990 founding, until mid 2016 — when editor in chief Linda Wells departed in a masthead shakeup.

“I hired him not long after I started Allure, he was really one of the early contributors to the magazine — we worked together for 25 years. We grew up together: We both got married, both had kids, our kids are the same age. So there was a personal side of it that we shared, all the angst and glory,” Wells said.

“When he first started contributing to Allure he had a knowledge that celebrities were becoming subjects of greater [public] fascination than they had been in a while — that shift from models to celebrities, he sort of predated it.

“So he went out and he did the most exhausting job known to mankind — he went and stood at red carpets and events and asked these bold and disarming questions that really elicited human responses. He had a way of cutting through the formality of those cases and getting something that we could all identify with,” Wells added.

Former Allure articles editor and current Town & Country site director Elizabeth Angell had long edited Slonim at Allure and had recently brought his work to T&C’s online site.

“He really invented a kind of celebrity moment on the red carpet where one asks questions that weren’t about their divorce. He would ask about their favorite movie, the book they were reading, what they like to do when they’re alone in an elevator — this quick snapshot of a celebrity’s life aside from fame was really something he pioneered,” Angell said.

Slonim was an inimitable presence at New York events, where as Wells says, “he was always dressed for the occasion, he looked like he belonged,” in varying degrees of tailored black-tie. Come the summertime Hamptons circuit, Slonim would trade his navy suiting for seersucker ensembles.

Said close friend and Yale classmate Alexander “Sandy” Ewing: “He was at the top of this field — it’s an unusual field — but he was at the top of it. He was admired and loved in a field where you can be easily hated by these celebrities, but Jeff was different, he was a real gentleman — he was beloved.”

Added Joan Kron, former Allure editor at large: “I think it was a contradiction for him to be covering celebrities because so often there can be a b—hiness on that beat, an overall ‘gotcha’ mentality. I think part of his success was that people trusted him to tell him personal things.”

After news of his death broke Sunday afternoon, fashion, art and high society insiders — including Glenn O’Brien, Zac Posen, Coco Rocha, Euan Rellie, Ivan Bart, Ariana Rockefeller, Cameron Silver, Jaime King and others — took to Twitter to relay their grief.

Per Ewing, a memorial service is being planned. A date and time have yet to be confirmed.