The 14 year-old "Stranger Things" star deleted her @milliebbrown account Wednesday.
The hashtag #TakeDownMillieBobbyBrown started last year, according to one Twitter user, when someone claimed in a tweet that the actress refused to take a picture with her unless she removed her hijab. When the woman refused, she alleges Brown then pulled off the hijab for her.
There is no evidence the incident actually occurred.
The hashtag was used to spread stories -- many of them with outrageous details -- falsely linking Brown to homophobia. (Brown has been an outspoken supporter of GLAAD's Together movement.)
Other social media users expressed support for Brown, who remains active on Instagram.
"Wowwwwwww humanity really is the worst," one person tweeted. "Y'all bullied Millie Bobby Brown into deactivating her Twitter? Hope you feel real good about tearing down a 14-year-old (who's more successful than you'll ever be)."
Brown is just the latest celebrity to be bullied online.
"The Last Jedi" star, Kelly Marie Tran, recently quit Instagram after months of racist backlash regarding the inclusion of her character, Rose Tico, in the film.
CNN has reached out to Browns reps for comment.