Details of the bill will be released in the coming weeks but Macron told journalists in a New Year address to the press that measures to boost transparency would include an oblication for the media to reveal all sponsors of their content.
The law would enable judges to order media to take down fake news, block access to offending websites, close social media accounts that spread untruths and even block offenders' internet access.
"We are going to develop our legal means of protecting democracy against fake news," Macron said.
"Thousands of propaganda accounts on social networks" are spreading "all over the world, in all languages, lies invented to tarnish political officials, personalities, public figures, journalists", he added.
During last year's presidential election campaign, thousands of internal documents from Macron's team were leaked online.
He branded the leak an attempt at "destabilisation of democracy like that already seen in the United States during the last presidential campaign".
France's broadcasting regulator will be given increased powers to better allow it to "fight any destabilisation attempt by television channels controlled or influenced by foreign states", Macron said.
This would allow agreements permitting such channels to operate in France to be "suspended or cancelled", also taking into account the content they publish online, he said.
RT launched a French-language channel in December.
The announcement comes after Germany this week passed legislation to fight fake news.
It puts social networks at risk of fines of up to 50 million euros if they do not remove fake news and hate-speech posts promptly.