Among the first to benefit from the initiative will be the International Consortium of Investigative Journalists.
Among the first to benefit from the Omidyar Network initiative will be the International Consortium of Investigative Journalists, which last year broke the "Panama Papers" corruption story, getting $4.5 million to expand its investigative reporting.
"Across the world, we see a worrying resurgence of authoritarian politics that is undermining progress towards a more open and inclusive society," said Omidyar Network managing partner Matt Bannick in a statement.
"A lack of government responsiveness and a growing distrust in institutions, especially the media, are eroding trust. Increasingly, facts are being devalued, misinformation spread, accountability ignored, and channels that give citizens a voice withdrawn.
"These trends cannot become the norm, and we must protect the principles of openness, participation, and accountability. These are the foundations of a healthy democratic society."
The pledge adds to the efforts of the network, which has previously funded independent media and fact-checking organizations.
Omidyar said in a tweet about the initiative: "The fight against misinformation, authoritarian lies, and online abuse is a fight we can win."
Omidyar himself has pledged to invest $250 million in his online news operations, which include the investigative new site The Intercept.
Other groups to benefit from the latest pledge include the Anti-Defamation League, which combats anti-Semitism, and the Latin American Alliance for Civic Technology (ALTEC), a project launched this year by Omidyar Network and others to support the technology platforms to promote civic engagement, government accountability, and transparency in Latin America.
Omidyar, a French-born Iranian-American, in 2013 launched First Look Media, which includes The Intercept and supports efforts to develop new technology platforms for media.