His salvo came as the social media giant prepares to hand over 3,000 political ads to congressional investigators that it has said were likely purchased by Russian entities during and after last year's presidential contest.
Trump appeared to embrace the focus on the social media network in his comments on Wednesday, which also took aim at more traditional medial outlets, long targeted by the president as "fake news."
"Facebook was always anti-Trump. The networks were always anti-Trump," Trump said on Twitter, leveling the same charge against the New York Times and the Washington Post. "Collusion?"
Representatives for Facebook did not immediately respond to a request for comment on Trump's tweet.
U.S. Representative Adam Schiff, the top Democrat on the House Intelligence Committee, which is among those investigating Russia's role, said he expected to have the ads by next week and that they should be made public.
"You really need to see them ... to recognize how cynical an effort this was by the Kremlin, how they sought to just accentuate those divisions ... and drive American against American," Schiff told MSNBC, adding that Facebook and Twitter Inc executives should testify publicly about the issue.
"I have concerns about how long it took Facebook to realize the Russians were advertising on their network," Schiff told MSNBC, adding that he has spoken several times with the company's chief executive, Mark Zuckerberg.
Facebook and other technology companies are coming under increased scrutiny amid the Russia investigations. The probes, being conducted by several congressional committees along with the Department of Justice, have clouded Trump's tenure since taking office in January and threatened his agenda, which has yet to secure a major legislative victory.
Moscow has denied any collusion.
Trump himself has previously praised Facebook and credited it with helping him win the November election. His campaign has said it spent some $70 million on Facebook ads, and it also ran a live Facebook show.
His latest comments did not appear to affect shares of the company, which were up 1.4 percent at $166.50 a share in late morning trading after analysts raised their price target for the stock.
(Reporting by Susan Heavey, David Ingraham and Makini Brice; Editing by Chizu Nomiyama and Jonathan Oatis)
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)