Claudia Sheinbaum, a climate scientist and former mayor of Mexico City, won her nation’s elections on Sunday in a landslide victory that brought a double milestone: She became the first woman, and the first Jewish person, to be elected president of Mexico.

Ms. Sheinbaum, 61, prevailed in what the authorities called the largest election in Mexico’s history, with the highest number of voters taking part and the most seats up for grabs.

It was a landmark vote that saw not one, but two, women vying to lead one of the hemisphere’s biggest nations. And it will put a Jewish leader at the helm of one of the world’s largest predominantly Catholic countries.

Ms. Sheinbaum, a leftist, campaigned on a vow to continue the legacy of Mexico’s current president and her mentor, Andrés Manuel López Obrador, which delighted their party’s base — and raised alarm among detractors. The election was seen by many as a referendum on his leadership, and her victory was a clear vote of confidence in Mr. López Obrador and the party he started.