Facebook declined to comment but pointed to recent announcements about what it's doing to limit the reach on its platform of groups that support violence and its efforts to protect the U.S. election in November.
With 188 million followers, Kardashian West is one of the most influential people on Instagram and support from her and other big names for the boycott saw Facebook shares slide in aftermarket trading late Tuesday. They were down 1.7% ahead of the market open on Wednesday.
The organizers behind "#StopHateforProfit," including civil rights groups such as the Anti-Defamation League, the NAACP and Color Of Change, had previously led a campaign that got hundreds of brands and nonprofits to join a Facebook advertising boycott in July.
Ashton Kutcher, Mark Ruffalo, Kerry Washington, Rosario Dawson, Jamie Foxx and Sacha Baron Cohen were among about two dozen Hollywood stars and celebrity influencers supporting the campaign, the organizers said.
DiCaprio said he was standing with the civil rights groups to call "on all users of Instagram and Facebook to protest the amplification of hate, racism, and the undermining of democracy on those platforms."
Facebook, which earned nearly $70 billion in advertising revenue last year, is facing a reckoning over what critics call indefensible excuses for amplifying divisions, hate and misinformation on their platforms.
"We are quickly approaching one of the most consequential elections in American history," organizers said. "Facebook's unchecked and vague 'changes' are falling dangerously short of what is necessary to protect our democracy."
The movement also singled out for criticism Facebook's handling of online material ahead of the shootings in Kenosha, Wisconsin last month.
CEO Mark Zuckerberg has said the company made a mistake in not removing sooner a page belonging to a militia group that called for armed civilians to enter the town.
It only took the page down after an armed teenager killed two people after violent protests sparked by the police shooting of Jacob Blake, who is Black.