The outdoor brands The North Face, Patagonia and Rei have withdrawn their advertising from Facebook platforms.
The Stop Hate For Profits campaign invites brands to join the boycott during the month of July.
The North Face said it stopped advertising "until more restrictive policies are put in place to prevent racist, violent or hateful content and disinformation from circulating on the platform."
Facebook said it was committed to "promoting racial fairness and justice".
"We are taking steps to review our policies, ensure diversity and transparency in making decisions about how to apply our policies and advance racial justice and voter engagement on our platform," he said in a long post, published Sunday.
Patagonia said it will also join the boycott until "at least the end of July".
A spokesman for VF Corp, owner of The North Face, told CNN that he was considering adding other brands to his boycott portfolio - he also owns Timberland and Vans.
Facebook has faced heavy criticism, including from its staff, for the decision of CEO Mark Zuckerberg not to remove a controversial post by U.S. President Donald Trump.
The same message was also shared on Twitter, where it was hidden behind a warning label because it "glorified violence".
Joseph Evans, technical manager of Enders Analysis, said that Facebook was trying to avoid further regulation by the United States government and to maintain advertising revenue.
"Facebook can endure a boycott from big companies better than any other media organization out there, as a large part of its revenue comes from smaller advertisers who are unlikely to come together to make political demands," he said.
"However, at the moment, many of these small advertisers are under pressure due to the fact that Covid-19 is drying up their cash flow. So we could see a perfect storm.
"What I expect to see is that Facebook is trying to walk a tightrope: interpreting its existing guidelines in a slightly more rigorous way, erring more on the side of eliminating the hate speech, but without much in terms of explicit policy changes that could result in punitive regulations or get Mark Zuckerberg dragged before another Senate committee. "
