King was spotlighted as an "Artist to Watch in 2012" by Esquire Magazine and made television appearances on VH1 Big Morning Buzz Live and the Late Show with David Letterman. King has played Austin, Texas, at the South by Southwest Festival, as well as the Hammersmith Apollo. She has also taped her own PBS Arts In Context special for KLRU Austin at the Austin City Limits recording studio. She toured with Of Monsters and Men, Train and Michael Kiwanuka and has opened for Dashboard Confessional, Dropkick Murphys, Dry the River, James Bay and Ed Sheeran.

King was born in Los Angeles, California, United States, to then–SNL cast member Rob Schneider. and London King, a former model. Her parents divorced and her mother remarried. She grew up living in southern Ohio, between Wellston and Columbus. When she was nine, her stepfather, Justin Tesa, gave her a record by all-girl hard-rock band The Donnas; she views this as the pivotal moment when she decided she wanted to be a musician. Around this time, she also started listening to The Runaways and Blondie, and she made her acting debut alongside her father in the movie Deuce Bigalow: Male Gigolo.

In September 2014, King released "Ex's & Oh's", which serves as the lead single off her debut album. She released the album, Love Stuff on February 17, 2015. She performed "Ex's & Oh's" the next day on The Today Show to promote it. The song has reached number 10 on the Billboard Hot 100, becoming King's first top 10 single in the United States. "Ex's & Oh's" received two nominations at the 58th Grammy Awards: Best Rock Performance and Best Rock Song. In July 2015, King supported Modest Mouse on their UK tour. Afterwards, "Under the Influence" and "America's Sweetheart" were released as singles for rock radio and mainstream radio, respectively. In 2016, her single "Good Girls" featured on the Ghostbusters Soundtrack and played over the movie's credits. In 2016, she teamed up with country singer Dierks Bentley for the song "Different for Girls". They performed this song at the 50th CMA Awards on November 2, 2016 where she and Bentley won the award for Musical Event of the Year.

King started dating Andrew Ferguson in January 2016. The couple got engaged in February 2016 on a sailing trip around the San Francisco Bay. They married on February 14, 2016 and confirmed their intent to divorce on May 15, 2017. However, recently King and Ferguson have started fresh from the last months of 2017, with King confirming they are continuing their marriage. They have since gotten back together towards the end of 2017.

She was featured on TLC's "Say Yes to the Dress" in February 2017.