McDormand, 60, also championed her female co-stars and all of the females in the room at the ceremony by asking them all to stand.
Calling on all the female winners and nominees to stand with her as she claimed the prize for her role in Three Billboards Outside Ebbing, Missouri, McDormand finished her speech with a phrase that left some viewers puzzled.
“I have two words to leave you with tonight ladies and gentlemen,” she said. “Inclusion. Rider.”
So what is an inclusion rider?
The phrase was coined by Dr Stacy Smith of the Annenberg Inclusion Initiative of Californian university USC Annenberg in a 2016 TED talk she gave titled “The data behind Hollywood’s sexism”.
Between 2007 and 2015, Dr Smith said she analysed more than 800 films and catalogued every speaking character by their gender, race, ethnicity, sexual orientation and disabilities.
Less than a third of all speaking roles are given to girls or women, she said, despite women making up half of the population. When it came to other demographics, the numbers were even more unbalanced.
Here is a full transcript of her Oscars acceptance speech from the Academy:
“Okay, so I’m hyperventilating a little bit. If I fall over, pick me up cause I’ve got some things to say.
“So I think this is what Chloe Kim must have felt like after doing back-to-back 1080s in the Olympic halfpipe. Did you see that? Okay, that’s what it feels like.
“I want to thank Martin McDonagh, look what you did. We are a bunch of hooligans and anarchists but we do clean up nice. I want to thank every single person in this building.
“And my sister Dorothy. I love you, Dot. And I especially want to thank my clan, Joel and Pedro “McCoen.” These two stalwart individuals were well-raised by their feminist mothers. They value themselves, each other and those around them. I know you are proud of me and that fills me with everlasting joy.
“And now I want to get some perspective. If I may be so honoured to have all the female nominees in every category stand with me in this room tonight, the actors - Meryl, if you do it, everybody else will, c’mon - the filmmakers, the producers, the directors, the writers, the cinematographer, the composers, the songwriters, the designers. C’mon!
“Okay, look around everybody. Look around, ladies and gentlemen, because we all have stories to tell and projects we need financed.
“Don’t talk to us about it at the parties tonight.
“Invite us into your office in a couple days, or you can come to ours, whatever suits you best, and we’ll tell you all about them.
“I have two words to leave with you tonight, ladies and gentlemen: inclusion rider”.