About 40 world leaders, including British Prime Minister, David Cameron, and German Chancellor Angela Merkel, are gathering in Paris ahead of a march to show unity after three days of terror that left 17 innocent civilians dead.
Other leaders expected at the rally are Palestinian leader Mahmoud Abbas and Israeli Prime Minister, Benjamin Netanyahu.
Sunday’s rally is expected to dwarf Saturday’s marches that saw 700,000 take to the streets.
About 2,000 police officers and 1,350 soldiers are being deployed across the French capital to protect marchers.
Police are seeking accomplices of the gunmen who attacked a satirical magazine and a kosher supermarket.
The interior minister says France will stay on high alert in the coming weeks.
Bernard Cazeneuve will host a meeting on Sunday morning of fellow interior ministers from across Europe to discuss the threat posed by militants.
Mr Cazeneuve promised “exceptional measures” for the massive unity march in Paris on Sunday, including positioning snipers on roofs.
The march, which will be led by relatives of the victims of last week’s attacks, will leave Place de la Republique at 15:00 local time (14:00 GMT).
More than a million people are expected to take part according to a BBC Paris report.