Facebook deleted the post from Trump's account that included a video of an interview with the president on Fox News during which the president suggested that children are generally "immune" to the virus.
"This video includes false claims that a group of people is immune from COVID-19 which is a violation of our policies around harmful COVID misinformation," Facebook representative Andy Stone said.
The decision marks the first time that Facebook has removed a Trump post for information related to the novel coronavirus.
In June, Facebook removed Trump campaign adds that featured a red, upside-down triangle, which the Anti-Defamation League said was similar to one used by Nazis for political prisoners, saying that it violated its policy against organized hate.
Twitter said Wednesday it restricted access to Trump's re-election campaign account for posting a tweet of the video.
A Twitter spokesman said in a statement that the video was in "violation of the Twitter rules on COVID-19 misinformation."
"The account owner will be required to remove the tweet before they can tweet again," the statement said.
The Trump campaign has deleted the tweet and has resumed tweeting.
Twitter has flagged several of Trump's tweets, doing so for the first time in May after the site determined two tweets the president made about mail-in ballots contained "potentially misleading information about voting processes."
Last month, the Commerce Department petitioned the Federal Communications Commission to develop plans to regulate social media platforms after Trump signed an executive order on the subject in May.