Mexico’s official electoral authority said preliminary results showed the 61-year-old former mayor of Mexico City winning between 58% and 60% of the vote in Sunday’s election.
That gives her a lead of about 30 percentage points over her main rival, businesswoman Xóchitl Gálvez.
Sheinbaum will replace her mentor, outgoing President Andrés Manuel López Obrador, on 1st October.
The election of a woman to the highest office was an emotional moment for some.
Sheinbaum, a former energy scientist, has promised continuity, saying that she will continue to build on the “advances” made by Mr López Obrador, further building on the welfare programmes which have made the outgoing president very popular.
But in her victory speech, she also highlighted what has set this Mexican election apart from previous ones. She told cheering voters: “For the first time in the 200 years of the [Mexican] Republic, I will become the first woman president of Mexico.”
She said it was an achievement not just for her but for all women.
“I’ve said it from the start, this is not just about me getting [to the top office], it’s about all of us getting here. I won’t fail you,” she said.
Sheinbaum also thanked her rival, Xóchitl Gálvez, who has conceded victory.
Mexico’s first female president breaks political glass ceiling. Prior to running for president, Sheinbaum was mayor of Mexico City, one of the most influential political positions in the country and one that is seen as paving the way for the presidency.
Sheinbaum, whose Jewish maternal grandparents immigrated to Mexico from Bulgaria fleeing the Nazis, had an illustrious career as a scientist before delving into politics. Her paternal grandparents hailed from Lithuania.
Both of her parents were scientists and Sheinbaum studied physics before going on to receive a doctorate in energy engineering.
She spent years at a renowned research lab in California studying Mexican energy consumption patterns and became an expert on climate change.
That experience and her student activism eventually earned her the position of secretary of the environment for Mexico City at the time when Andrés Manuel López Obrador was mayor of the capital.
In 2018 she became the first female mayor of Mexico City, a post she held until 2023, when she stepped down to run for president.
The election, which pitted Ms Sheinbaum against Ms Gálvez, has been described as a sea change for women in Mexico.
Edelmira Montiel, 87, said that she was grateful to be alive to see a woman elected to the top office.
“Before, we couldn’t even vote, and when you could, it was to vote for the person your husband told you to vote for. Thank God that has changed and I get to live it,” she said.
While the fact that the two front-runners were women was widely celebrated, the campaign was marred by violent attacks.
Apart from a new president, voters also elected members of Mexico’s Congress and governors in eight states, the head of Mexico City’s government, and thousands of local officials.
The government says more than 20 were killed across Mexico in the run-up to the vote, although other surveys put the total at 37.
Ms Gálvez harshly criticised the government and her rival in the presidential race for the violence which blights large parts of Mexico.
She had promised to be “the bravest president, a president who does confront crime” if elected, but failed to provide details about how she would tackle the powerful criminal cartels which are behind much of the violence.