Padilla's political career began in 2001 when he was elected to the Los Angeles City Council. He served on the council for eight years, representing the 7th district.
In 2009, he was elected to the California State Senate, where he served as the Senate Majority Leader from 2014 to 2018.
In 2018, Padilla was elected Lieutenant Governor of California, serving under Governor Gavin Newsom.
In 2021, he was appointed to the United States Senate by Newsom to fill the seat vacated by Vice President Kamala Harris.
Padilla is a member of the Democratic Party.