His win has created enormous expectations for the 64-year-old, whose ambiguity on thorny issues allowed him to appeal to vastly divergent constituencies.
"I hope and I pray to God they give me an audience to see if he can help me get my savings back," said Maria Guadalupe Sanchez, a 58-year-old with a walking stick and a bad leg. "Because the truth is I'm dying of hunger."
Sanchez was one of many petitioners on Tuesday who waited for hours for a glimpse of Lopez Obrador, a former mayor of Mexico City who spent 13 years traversing the country's poorest villages to drum up support before winning the presidency at the third time of asking.
She blames the outgoing government of President Enrique Pena Nieto for the loss of her savings in a 2014 scandal that engulfed local lender Ficrea and affected thousands of Mexicans. Many are still battling to recover their money.
"Now I'm here hoping that Lopez Obrador can help us," said Sanchez, who told Reuters she fallen into such despair about her situation that she had tried to commit suicide several times.
Critics of Lopez Obrador cast him as a messianic populist with authoritarian leanings, but his willingness to campaign time and again in places rarely visited by politicians helped him capture the biggest mandate for any Mexican leader in decades.
His office, in the scruffily elegant streets of hip Mexico City neighborhood Roma, will be the setting for his meeting on Friday with U.S. Secretary of State Mike Pompeo, President Donald Trump's son-in-law and adviser Jared Kushner, and U.S. Treasury Secretary Steven Mnuchin.
Lopez Obrador has said he will eschew the traditional presidential bodyguard, give up the official residence and cut his salary in half as he seeks to root out corruption in Mexico's political class.
Mobbed regularly when he was mayor, he has cultivated a proximity to the people that has sent Mexicans flocking to his Roma bunker.
"What I want is a formal job, to be able to speak to Mr Obrador or someone who can talk to us to ask, to suggest to him that he gives us an opportunity to work," said Diego Tapia, a blind 26-year-old who gives massages on the streets of the city.
A woman in charge of registering the dozens of daily requests for Lopez Obrador said the number was rising.
"They ask for everything, there are tons," she said.