It is “common knowledge” in Hollywood that Ellen DeGeneres treats people “horribly” — and her bosses at Warner Bros. now face a tough decision over how to handle the comic and her lucrative TV deal, insiders tell Page Six.

After multiple people described a “toxic culture” at Ellen’s show, the host shifted the blame to her executive producers, saying on Thursday, “I’m … learning that people who work with me and for me are speaking on my behalf and misrepresenting who I am.”

Then “Everybody Loves Raymond” actor Brad Garrett tweeted of the mistreatment, “It comes from the top … [I] know more than one who were treated horribly by her. Common knowledge.” “Back to the Future” actress Lea Thompson added her voice to the throng, replying to a tweet about Garrett’s statement with “True story. It is.”

One Hollywood insider said DeGeneres was known to unleash attorney Marty Singer on people she felt had crossed her.

Another Hollywood insider told Page Six: “Everybody knows Ellen is mean and incredibly difficult. Now that Warners has launched an investigation, there are a lot of employees coming forward with accounts they can’t ignore.

“This puts Warners in a difficult position contractually with Ellen — they put hundreds of millions of dollars into their deal with her. If they decide they want her out — which looks increasingly likely — this will be a big legal problem. Plus, she’d never leave without her reputation intact.”

The source added, “The other big problem is there is no replacement for Ellen.”

In 2016, DeGeneres established the Ellen Digital Network under Warner Bros. Last May, when she ultimately signed a new deal to continue her daytime talk show through 2022, she said she was “torn” on how long to keep the show since she planned to produce documentaries through her digital subsidiary. Her company, A Very Good Production, is also behind series for NBC and Discovery Channel as well as film adaptations.

Reps for DeGeneres and Warner Bros. didn’t comment. The company said in a statement Thursday, “We are disappointed that the primary findings of the investigation indicated some deficiencies related to the show’s day-to-day management.”