The star - who joins Melissa McCarthy, Kristen Wiig and Kate McKinnon in the reboot of the 1980s classic blockbuster - has been attacked by bullies on Twitter, with some even comparing her to Harambe the gorilla.
She told one user they must "hate" themselves after they wrote: "Don't let #Ghostbusters bombing get you down. You're a shoo-in to star in the Harambe motion picture as the man himself. (sic)"
Leslie was understandable fuming, and fired back: "You think calling me a gorilla is funny you're sick. And very very sad. You must hate yourself to put out that kind of hate"
The tweet referred to the tragic death of Harambe the gorilla, who was shot dead at Cincinnati Zoo in Ohio, US, after a three-year-old boy entered his enclosure
In response to the vile tweets - many of which are too offensive to mention here - the actress began screenshotting them to name and shame the bullies.
She hinted that the comments have made her question her faith in humanity, and summed up the abuse she has been receiving.
She tweeted: "Ok I have been called Apes, sent pics of their asses,even got a pic with semen on my face. I'm tryin to figure out what human means. I'm out (sic)"
However, many fans did speak out to defend the star from the haters.
One replied: "Reading @Lesdoggg's timeline disgusted by people's ingorance. It's sad how immoral + cruel people become behind an avatar + a fake name (sic)"