"Our analysis suggests these accounts and Pages were affiliated with one another and likely operated out of Russia," Facebook's chief security officer, Alex Stamos, wrote in a post published on Facebook's company blog.
These sums were spent on advertisement with the social network between June 2015 and May 2017.
The operation involved 3,000 separate ads over a two-year period and was likely to have been run out of Russia.
About half of the funds potentially purchased ads intended to influence U.S. politics.
Though most of the ads did not reference the U.S. presidential election or a specific candidate, they did mention "divisive social and political messages" about subjects including LGBT rights, race issues, immigration and gun control.
Facebook has shared its findings with U.S. authorities.