Social networks should be held responsible for what their users say online by the creation of a new European legal framework, he said in Paris on Tuesday.
Hollande referred to "well-known large operators" without naming them -- but companies such as Facebook, Google and Twitter are typically the target of such remarks.
They should be subject to sanctions in case of a breach of the proposed rules, Hollande said, adding that he plans to present a draft law to fight racism and anti-Semitism to the French government by the end of February, including proposals for measures to curb hate speech on the Internet.
Google declined to comment on his proposals, while Twitter and Facebook did not immediately responded to a request for comment.
Hollande unveiled his plans during a memorial service for Jews deported in World War II, after the Union of French Jewish Students (UEJF) and the Union of Former Deportees launched a new campaign against Holocaust denial on social networks.
Such companies "cannot close their eyes" and will be considered an accomplice in the transmission of hate messages, Hollande said.
He also referred to the series of killings earlier this month that began at the offices of the French satirical magazine Charlie Hebdo and ended with a shoot-out at a kosher supermarket.
Since those shootings, calls to clamp down on social networks have become louder. European Union justice and home affairs ministers for instance issued a statement after the attacks in which they said it is essential to stem online terrorist propaganda in a close cooperation with ISPs.
Though such a measure could be illegal, the ministers are set to talk about how to implement anti-terror measures such as this in Riga on Thursday and Friday. There, they will also discuss plans to force Internet firms to hand over encryption keys to EU law enforcement as well as a revised European Commission plan to collect and store passenger flight data for up to five years to help law enforcement track down terrorists.
Putting a lid on what people can say or post on social media is not only a strategy favored by European countries. Facebook for instance was forced to block some content in Turkey this weekend after a court ordered a ban on material that it considered insulting to the Prophet Muhammad.
Loek is Amsterdam Correspondent and covers online privacy, intellectual property, online payment issues as well as EU technology policy and regulation for the IDG News Service. Follow him on Twitter at @loekessers or email tips and comments to loek_essers@idg.com