Badenoch, who was raised in Nigeria, is the first black woman to lead a major political party in the UK.
She takes over from Rishi Sunak, who led the Conservatives to their worst ever election defeat in July.
During her campaign, Badenoch vowed to return the Conservatives to "first principles" and launch a series of reviews in the coming months to shape a new policy platform.
She is also the sixth Tory leader in less than eight and a half years and faces the challenge of uniting a fractured party.
In her victory speech, Badenoch told members it was "time to tell the truth” and “get down to business".
Her "first responsibility" as the new Tory leader "is to hold this Labour government to account," she said.
"Our second is no less important - it is to prepare over the course of the next few years for government."
The final result saw Badenoch win with 53,806 votes compared to Jenrick's 41,388 votes.
All eyes will now turn to who Badenoch chooses for her shadow cabinet as she sets out the future shape of the party.
Only a third of Conservative MPs backed Badenoch in her leadership win.
Badenoch previously said she would offer a frontbench job to all six of her rivals in the leadership race, including Jenrick.
But shadow home secretary James Cleverly, who came third in the race, has already ruled himself out of a frontbench role.
