Born and raised in Haugesund, Sundfør embarked on her musical career two years prior to the release of her eponymous debut album (2007), which reached number three on the Norwegian album chart. It was followed by Take One, a live album consisting of songs from her debut. Her second studio album, The Brothel, was released in 2010 to commercial success in Norway, peaking at number one and becoming the best-selling album of that year. The album saw a shift from the piano-driven pop from previous releases towards a more ambitious and electronic sound. In 2011, she released a live instrumental album composed solely of synthesizers, A Night at Salle Pleyel, serving as a commission piece.
Her third studio album, The Silicone Veil (2012) topped the Norwegian album chart and received critical acclaim.
On 6 December 2013, she released a collaboration with the Norwegian electronic duo Röyksopp, "Running to the Sea".
Sundfør collaborated with French electronic band M83 on the soundtrack for the 2013 film Oblivion. The soundtrack was released on 9 April 2013 and features the title song "Oblivion" with Sundfør contributing the main vocals. That year she also produced, programmed, arranged, recorded, provided backing vocals and played the keyboards and autoharp on the indie pop band Bow to Each Other's debut album The Urge Dreams, marking her debut as a producer.
In 2015, she had her international breakthrough with her fourth studio album, Ten Love Songs, which saw Sundfør experimenting with an electronic dance pop sound. The album reached number one and garnered universal acclaim.
She appears on the the M83 track "For The Kids" from their 2016 album Junk.
Her fifth studio album Music for People in Trouble (2017) represented a departure from the electronic-driven sound of previous records in favor of a return to her roots as a folk singer-songwriter. The album reached number one as well, making it her fourth consecutive album to achieve this feat.