In 2012, Badenoch unsuccessfully contested a seat in the London Assembly, but became a member of the London Assembly after Victoria Borwick was elected as an MP in 2015. A supporter of Brexit in the 2016 referendum, Badenoch was elected to the House of Commons at the 2017 general election.
After Boris Johnson became prime minister in July 2019, Badenoch was appointed Parliamentary Under-Secretary of State for Children and Families. In the February 2020 reshuffle she was appointed Exchequer Secre