President Macron has asked Algerians who fought for France during Algeria's war of independence for forgiveness.
He was heckled as he admitted France had failed in its duty to the group - known as the Harkis.
Many lived in poor conditions behind barbed fenced wires after the government refused to recognise their rights to stay in France, according to the AFP news agency.
Those remaining in Algeria faced savage reprisals as collaborators.
Speaking to an audience of Harkis and their descendants in Paris, Mr Macron promised legislation on reparations as well as a monument.
"In the name of France, I say to the Harkis and their children in a loud and solemn voice, that the Republic has contracted a debt towards them. To the combatants, I wish to express our gratitude.
"We will not forget. To the abandoned combatants, to their families who suffered the camps, the prison, the denial, I ask forgiveness, we will not forget."
Monday's speech marks the latest in a series of attempts by the French president to address historical grievances with Algerians in the hope of improving relations between the two countries, which have been fraught since Algeria's independence in 1962.
In March, his government admitted its army tortured and killed a prominent Algerian activist more than 60 years ago.
Around 300 former Harkis - who derive their name from the Arabic word for movement - were invited to hear Mr Macron speak, according to the Reuters news agency.
During the speech Mr Macron also outlined plans for a commission to hear about the squalid French camps former fighters and their children were forced to live in.
It is estimated that up to 200,000 Harkis fought for France during the eight-year war, but only 42,000 were allowed to relocate to France after Algeria gained independence, AFP reports.
Tens of thousands of those left in Algeria were labelled as traitors and killed.
Previous presidents have offered apologies, but Harki leaders said a $50m (£37m) hardship fund announced three years ago was wholly inadequate.
Some in the crowd repeatedly interrupted President Macron, including one woman who accused him of "empty promises", according to the France24 site.
However, others welcomed his plea for forgiveness.
Serge Carel - a former Harki - thanked the president.
"It seems that for the first time, a firm desire for the truth is guiding our current president. Thank you for your attention, long live the Republic, long live France."