Hollande made the appeal after a tribute to the 130 victims of the Paris attacks, during which he vowed to destroy the “army of fanatics” behind the violence that rocked the French capital two weeks ago.
“On November 13, a day we will never forget, France was hit at its very heart,” Hollande told a sombre commemoration in the Invalides, the 17th-century complex housing Napoleon's tomb on Friday.
“To all of you, I solemnly promise that France will do everything to destroy the army of fanatics that committed these crimes,” he said.
Speaking later at the Commonwealth summit in Malta, where he flew after the ceremonies in Paris, Hollande called on British lawmakers to support France's intervention in Syria.
“I can only call on all British members of parliament, in solidarity with France but, above all, conscious of the fight against terrorism, to approve this intervention,” he said.
Hollande has already been backed by Germany, which has offered Tornado reconnaissance jets, a naval frigate, and 650 soldiers to relieve French forces in Mali.
British Prime Minister David Cameron made his case for air strikes to parliament on Thursday ahead of a vote expected next week.
But many MPs are still troubled by the memory of unpopular British interventions in Iraq and Afghanistan under then Labour prime minister Tony Blair.
The Stop the War Coalition — which also led demonstrations against British intervention in Iraq — has organised a major rally in London to protest the move, with thousands expected to march on Downing Street on Saturday
“We are calling on all our groups to organise protests in their towns and cities on the same day. We need to resist this brutalising and dehumanising spiral of violence,” the group said on a Facebook page to advertise the event.
Spanish activists also called for peace protests on Saturday, with the country still scarred from extremist attacks following its involvement in the Iraq war.
The 2004 attacks saw Al-Qaeda-inspired bombers blow up four packed commuter trains and kill 191 people in retaliation for then prime minister Jose Maria Aznar's decision to join the US-led Iraq invasion.
Leading personalities, including Barcelona Mayor Ada Colau and Pilar Manjon, head of an association for victims of Madrid's attacks, have called for nationwide peace protests to denounce the use of further force.
Their online manifesto has been signed by more than 28,000 people and demonstrations are planned in Madrid, Barcelona, Seville and Valencia and other locations.
France has said that all 27 of its EU partners have pledged to help in some way to strike at the Islamic State group, but Spanish Prime Minister Mariano Rajoy has so far remained evasive on the issue.
The Paris attacks — claimed in response for French air strikes on the jihadists in Iraq and Syria — inflicted the worst-ever toll on French soil, leaving 130 dead and 350 wounded. Most victims were under 35.