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, reported BBC.
She defeated her key opponent Xóchitl Gálvez by a massive margin.
Sheinbaum,61, will replace outgoing President Andrés Manuel López Obrador on October 1.
In her victory speech, Sheinbaum, who is a former energy scientist, promised her voters that she won't fail them.
Sheinbaum served as Head of Government of Mexico City, a position equivalent to that of a state governor, from 2018 to 2023.