Allen was born in Southampton, Hampshire and grew up in the city's Swaythling and St Denys areas. She attended St Denys Primary School, Cantell School, and Eastleigh College. She started writing music when she was 14 years old and reached the final of a local talent competition in 2009. At 18 years old, she considered training as a beauty therapist, but her sister persuaded her to move to London to pursue her singing ambitions. She attended the Institute of Contemporary Music Performance but dropped out, preferring to write and perform music than study it.
Foxes said in a late 2014 interview that she had commenced work on her second album. She collaborated with veteran dance producer Giorgio Moroder on his 2015 solo album, Déjà Vu, featuring on the track "Wildstar". She has also been writing material for other recording artists. In an April 2015 interview, Foxes said that recording for her second album was finished and that she hoped to release it in late 2015. The album's first single, "Body Talk", is released in July 2015. Foxes debuted the track during a one-day tour of seven UK cities that earned her an entry to the Guinness World Records for the title of "most live concerts in 12 hours in multiple cities".