Anna Margaret Michelle Calvi (born 24 September 1980) is an English singer-songwriter and guitarist. Her accolades include three Mercury Prize nominations, one Brit Award nomination, and a European Border Breakers Award. She has been noted by some critics as a virtuoso guitarist, as well as for her powerful, wide-ranging operatic contralto voice and sometimes androgynous stage appearance.

Born to therapist parents in London, Calvi graduated from the University of Southampton with a degree in music, having studied violin. She subsequently worked as a private guitar instructor before embarking on a music career. She released her eponymous debut album in 2011 through Domino Records to critical acclaim, earning a Mercury Prize nomination for Album of the Year, a British Breakthrough Act nomination at the 2012 Brit Awards and a European Border Breakers Award.

Her second album, One Breath, was released in 2013, earning her a second Mercury Prize nomination. She followed this in 2014 with the EP Strange Weather and subsequently wrote the music for a stage production of the opera The Sandman, directed by Robert Wilson. Calvi released her third full-length album, Hunter, in August 2018, earning her a third Mercury Prize nomination.

Anna Margaret Michelle Calvi was born on 24 September 1980 in London, the younger of two children born to an English mother and Italian father, both therapists and "amateur musicians." Her sister Nuala Calvi is a journalist. Calvi spent most of the first three years of her life in a hospital undergoing treatment and surgeries to correct congenital hip dysplasia. "The way I dealt with that was to create my own world. And that's what my relationship with music is – a world of my own creation that I escape into. I was always a dreamer. The early things stick with you," she later remembered. Calvi grew up being exposed to a multitude of genres by her music-loving father; as well as her grandfather, with whom she spent summers in Rome. This eclectic array ranged from Captain Beefheart to The Rolling Stones to Maria Callas, combined with classical music: "I was so taken by the sound. Whenever I saw an instrument I would get so excited and my heart would beat really fast."

Calvi began playing violin at the age of six, before beginning to learn guitar at age eight. By the age of ten she was using a double cassette karaoke machine to overdub her guitar playing. She frequently played along to the records of Jimi Hendrix, whom she idolized. She also came to be much influenced by 20th century composers Messiaen, Ravel, and Debussy, attracted "to the impressionistic element of the music," and would try to recreate this feeling on the guitar.

When Calvi was 18 years old, she came out to her family as lesbian. After graduating from secondary school, Calvi enrolled at the University of Southampton, where she studied violin and guitar, graduating with a Bachelor of Arts degree in music in 2003. Following her completion of university, Calvi returned to London and worked as a guitar instructor, giving private lessons, though she reflected: "I was rubbish because I had taught myself so I couldn't explain how to play." She also worked as a sales assistant in a toy shop.

Calvi did not begin singing until her mid-late-twenties. "I had a phobia about it until five years ago," she said in 2011. "I wouldn't sing in school or even in the shower. I had this emotional block about hearing my voice. So the guitar became my voice when I was a teenager, it was how I could express myself." In an effort to find her own voice, Calvi has spoken of how she would lock herself in a room for long periods of time, singing along to records by Edith Piaf and Nina Simone.

Calvi formed several bands, including Cheap Hotel, who released one download-only single ("New York"), which did not chart. Calvi later met multi-instrumentalist Mally Harpaz and drummer Daniel Maiden-Wood, who eventually formed her band. While playing in bands and giving guitar lessons, Calvi was privately recording songs on an eight-track recorder in the attic of her parents' home. At an early gig, Calvi caught the attention of Bill Ryder-Jones who urged Laurence Bell of Domino Records to sign her. Early support also came from Brian Eno, who heard about Calvi through a friend. Calvi played guitar on the track "The Prizefighter and the Heiress" on Johnny Flynn's album Been Listening, and in October 2009 she went on to support Flynn on tour. In December 2009, she signed a recording contract with Domino Records.