The head of G/O Media, which owns The Onion, Jezebel and other popular websites, is going on the defensive over a planned expose on his hiring practices — to be published by one of his own reporters.

G/O Media’s CEO, Jim Spanfeller, is punching back at a yet-to-be-published report by Deadspin about his hiring of “older white guys” from his past to run the company, which also runs Gizmodo, Splinter and The Root.

As The Post reported on July 18, G/O Media staffers have been complaining that Spanfeller — tapped to run the dozen websites by private equity firm Great Hill Partners earlier this year — has been relying on his connections from Playboy and Forbes Media to run the company without posting jobs publicly.

Instead of waiting for the Deadspin report to hit., Spanfeller circulated a three-page memo to all G/O Media staffers blasting the G/O web site’s reporting process, including complaints that he was not given enough time to respond to questions.

“I and the management team received a list of questions from the reporter working this story for Deadspin and those questions left me greatly concerned about the objectivity and core intentions of this piece,” Spanfeller’s memo said. “While we were given a 3 pm deadline today to respond to dozens of questions, I understand that the folks at Deadspin have already submitted their story for legal review and plan to publish it on Wednesday — all without ever seeing any of the responses to the questions that they asked.”

Deadspin’s report investigating the complaints had been set to be published on Wednesday morning, according to a rep from G/O.

Deadspin editor in chief Megan Greenwell denied that the report is scheduled to be published Wednesday, saying it was sent to legal department Tuesday in anticipation of a “lengthy process.”

“We are in an ongoing reporting process and planning to publish the story when it is ready. As with any reporting process, we asked questions intending to incorporate the answers,” Greenwell said. “Legal review is often a lengthy process involving multiple reads, so talking to a lawyer is certainly not an indication that we would publish without completing the reporting process. I intend to continue supervising the reporting process, including legal review, and then publish a thorough and fair story, which of course would include responses from people we spoke to.”

G/O’s legal department, which was reviewing the story, alerted Spanfeller that Deadspin had filed the story with legal without including any of management’s answers to its questions, one insider told The Post.

Deadspin’s questions and management’s answers, which were also circulated by Spanfeller, were directed at both Spanfeller and his new hires, including chief technology officer Jesse Knight, senior vice president of marketing Bruce Rogers, editorial director Paul Maidment and Sean Flanagan, a vice president of sales.

“How many of these men would you call your friends?” one of the questions to Spanfeller read.

“I’ve had professional relationships with some of them. I have not socialized outside work and industry related events with any of them,” Spanfeller responded.

Questions posed to his new hires also explored their relationships with the CEO, as well as Spanfeller’s oversight of their jobs. One particularly striking query tackled editorial independence, a sticking point for staffers at G/O, which even have a clause in their union contract that leaves all editorial decisions to writers and editors and demands stories be killed by committee.

The company, whose properties used to be part of the now-troubled Gawker Media empire, has a track record of investigating and jabbing its owners.

Among the questions circulated Tuesday was Deadspin’s asking Maidment, the new editorial director, about sources who have claimed he “is unwilling or unable to stand up for your team.”

He replied: “I take strong exception to that. I have always shielded the editorial teams I have managed from commercial or business-side interference in what they write, which to my mind is the essence of editorial integrity. As you know, one reason that I don’t believe that publications should write about themselves is because I fear it damages perceived external credibility in editorial independence, which, if anything, makes keeping advertisers at bay harder, not easier.”

Earlier this month, The Daily Beast reported that G/O management suggested that reporters take ad sales execs to editorial meetings with sources.

Spanfeller has suggested hiring a public editor to tackle the story and other internal investigations, but the hiring process takes time.

The exec expressed “great sadness” by the turn of events and said he hopes to tackle questions at an all-hands meeting on Wednesday.

“As CEO, I am fine with taking the heat, it is in my job description. But to try to shame and discredit others in our community, as some questions seem designed to do, is quite unfortunate,” he concluded.