Mr Gassama arrived in France past year. The undocumented migrant will be given French papers. "I was trembling", he told Macron.
The video went viral and Gassama, who has been nicknamed "Spider-Man" for conducting the rescue in less than a minute, was swiftly granted a meeting at the Elysee Palace.
He said that when he reached the apartment, he became scared and started shaking.
By the time Parisian emergency services arrived at the building, he had already pulled the child to safety.
After less than a minute, the Malian hero grabs the four-year-old toddler while a neighbour tried to hold the child from an adjoining flat.
The video of him pulling himself up from balcony to balcony with supreme ease has been viewed millions of times on social media, propelling him to stardom.
Lassana Bathily helped hide hostages in the freezer during an Islamist jihadi attack on a Jewish supermarket, in which four people were killed.
Across the political class, Gassama received plaudits.
Le Parisien newspaper reported that Gassama was walking by when he saw a gathering in front of the building and leapt into action.
Passers-by raised the alarm Saturday on noticing the little boy hanging in mid-air.
Mamoudou Gassama is now a symbol of hope and courage in a country that had been longing for new heros. His mother was out of Paris and his father will now be questioned for leaving the child unattended. His mother was overseas.
"He explained to me that he arrived from Mali a few months ago while dreaming of building his life here", she said.
The family of the young boy he saved thanked him Tuesday for his quick thinking.
His home, which he shares with relatives, is a cramped 15-square-metre room in a migrant workers' hostel, with a mattress on the floor for a bed.
"What you have done corresponds with what firefighters do; if this fits your wishes, you could join the firefighters' corps so that you can do [such acts] on a daily basis", Mr Macron said.
In an interview with BFM TV, Gassama said once he had the boy safely in his arms, he asked him why he did that, but the child, probably in shock, did not initially reply.