For years, HBO’s post-Golden Globes party has been the most coveted invitation of the night.

But this year, the sheen is off.

The bash, always held in the Beverly Hilton’s Circa 55 restaurant, is now plagued by a budget crunch, major in-house losses — and just one lonely nomination for its previous big winner, “Game of Thrones” (Best Actor in a TV Drama for Kit Harington).

Sure, HBO got 15 noms total for 2019 including for “Barry,” “Succession,” “Chernobyl” and “Big Little Lies,” all very buzzy. But when parent company Time Warner became part of AT&T in 2018, the network shed some executives who were incredibly popular in Hollywood — among them, former Chairman and CEO Richard Plepler (now with a new deal at Apple TV), head of entertainment publicity Nancy Lesser and longtime “GoT” publicist Mara Mikalian, not to mention the retirement of documentary guru Sheila Nevins.

In losing Lesser, the network also lost some of the party’s soul: She had produced the post-Globes and Emmys mega-soirees for years with planner Billy Butchkavitz.

HBO also allegedly had to give up a chunk of its party budget in the merger.

“AT&T is more interested in the next ‘Game of Thrones’ than the décor of an awards show party,” said a former HBO employee. “Billy went all around the world scouring pieces for exotically themed parties. The budgets were off the charts.”

For this year’s Emmys, the former employee added, they cut the budget and the guest list — and served less food.

“The stars, the journalists, the guests could feel it,” said a network insider of the downsized Emmys fete. “It’s just not the HBO of yore anymore.”

“There has been no decrease in our budget,” an HBO spokesperson told The Post.

For Sunday’s Globes party, the network insider said, AT&T also stripped some of the exclusivity by allowing employees of its other entertainment ventures, including TNT, to bring their advertisers.

Now, insiders predict, the hot bashes are likely to be those thrown by Amazon and Netflix.

Amazon’s Jeff Bezos, the world’s richest man, is now a celeb himself, showing up on David Geffen’s yacht and partying on the social circuit with the likes of Katy Perry and Little Nas X. Ted Sarandos, Chief Content Officer of Netflix, has also seen his personal and social star rise in starry circles.

“Is there an actor, stand-up comic or rock star who wouldn’t kill for a Netflix gig?” asked one Hollywood production vet. “If Martin Scorsese can make a Netflix movie, then it’s only a matter of time until Spielberg softens his no-streaming stance.”

Meanwhile, Sarandos’ wife, Nicole Avant, was a big Obama fundraiser and US Ambassador to the Bahamas. Her father, Clarence Avant, was the chairman of Motown Records and Nicole grew up at an estate visited by Jimmy Carter, Tom Bradley and Jerry Brown. She’s both political and Hollywood royalty.

Last year’s Amazon fete in the Hilton’s Stardust Penthouse saw Timothée Chalamet busting moves on the dance floor, plus Amazon Prime Video stars Rachel Brosnahan and Hugh Grant, This year’s is likely to be even buzzier thanks to star of the moment Phoebe Waller-Bridge of “Fleabag.”

“The streamers are where it’s at,” said one veteran awards-show party planner. “We were always jealous of Billy’s reign at HBO. Now we’re all throwing bids at Netflix and Amazon.”