The reality star said she would be “freezing” her accounts on the social media platforms on Wednesday and urged others to do the same.
She added that inaccurate social media posts have “a serious impact on our elections and undermines our democracy”.
“I love that I can connect directly with you through Instagram and Facebook, but I can’t sit by and stay silent while these platforms continue to allow the spreading of hate, propaganda and misinformation – created by groups to sow division and split America apart – only to take steps after people are killed,” she said.
She shared the message alongside the #StopHateForProfit hashtag, which is being widely shared by people criticising the social media companies.
Kardashian West has 188 million Instagram followers, while her Facebook page has been liked my more than 29,000,000 people.
Comedian Sacha Baron Cohen and actors Jennifer Lawrence and Mark Ruffalo and Ashton Kutcher have also posted in support of the #StopHateForProfit campaign.
Amazing - every hour, more people are joining tomorrow's Instagram freeze to tell Facebook to #StopHateForProfit
Advertisers, FB employees and users are fed up.
Facebook - stop spreading the hate, lies and conspiracies that inflame our societies!@NAACP@ColorOfChange @ADL pic.twitter.com/lrI8l7SRfY
— Sacha Baron Cohen (@SachaBaronCohen) September 15, 2020
These tools were not built to spread hate, violence, and misinformation, but when companies and individuals benefit from these behaviors, financially or otherwise, it becomes their responsibility to mitigate the unintended utilization. #StopHateForProfit https://t.co/s54jmjfmRg
— ashton kutcher (@aplusk) September 15, 2020
Facebook, which owns Instagram, has previously said it is taking steps to tackle disinformation online.
The platform's vice-president for northern Europe Steve Hatch says they're trying to get the balance right.
"We always want to improve, but equally we want to ensure we do that in an accurate way as well.
"I think we all want to take these things down faster, but also to make sure that we are not taking down the wrong content and that we are allowing debates to happen at the same time."