Roberta Joan Mitchell CC (née Anderson; born November 7, 1943) is a Canadian and American singer-songwriter, multi-instrumentalist, and painter. As one of the most influential singer-songwriters to emerge from the 1960s folk music circuit, Mitchell became known for her personal lyrics and unconventional compositions, which grew to incorporate elements of pop, jazz, rock, and other genres. Among her accolades are eleven Grammy Awards, and induction into the Rock and Roll Hall of Fame in 1997. Rolling Stone, in 2002, named her "one of the greatest songwriters ever", and AllMusic, in a 2011 biography, stated "Joni Mitchell may stand as the most important and influential female recording artist of the late 20th century."

Mitchell began singing in small nightclubs in Saskatoon and throughout western Canada, before moving on to the nightclubs of Toronto. She moved to the United States and began touring in 1965. Some of her original songs ("Urge for Going", "Chelsea Morning", "Both Sides, Now", "The Circle Game") were first recorded by other singers, allowing her to sign with Reprise Records and record her debut album, Song to a Seagull, in 1968. Settling in Southern California, Mitchell helped define an era and a generation with popular songs such as "Big Yellow Taxi" and "Woodstock" (both 1970). Her 1971 album Blue is often cited as one of the greatest albums of all time; it was rated the 30th best album ever made in Rolling Stone's 2003 list of the "500 Greatest Albums of All Time", rising to number 3 in the 2020 edition. In 2000, The New York Times chose Blue as one of the 25 albums that represented "turning points and pinnacles in 20th-century popular music". NPR ranked Blue number 1 on a 2017 list of the "Greatest Albums Made By Women".

Mitchell began exploring more jazz-influenced ideas on 1974's Court and Spark, which featured the radio hits "Help Me" and "Free Man in Paris" and became her best-selling album. Mitchell's vocal range began to shift from mezzo-soprano to that of a wide-ranging contralto around 1975. Her distinctive piano and open-tuned guitar compositions also grew more harmonically and rhythmically complex as she melded jazz with rock and roll, R&B, classical music and non-Western beats. Starting in the mid-1970s, she began working with noted jazz musicians including Jaco Pastorius, Tom Scott, Wayne Shorter, Herbie Hancock, and Pat Metheny as well as Charles Mingus, who asked her to collaborate on his final recordings. She later turned to pop and electronic music and engaged in political protest. She was awarded the Grammy Lifetime Achievement Award in 2002.

Mitchell produced or co-produced most of her albums and designed most of her own album covers, describing herself as a "painter derailed by circumstance". A critic of the music industry, she quit touring and released her 19th and last album of original songs in 2007. She gave occasional interviews and made appearances to speak on various causes over the next two decades, though the rupture of a brain aneurysm in 2015 led to a long period of recovery and therapy. A series of retrospective compilations were released over this time period, culminating in the Joni Mitchell Archives, a project to publish much of the unreleased material from her long career. She returned to public appearances in 2021, accepting several awards in person, including a Kennedy Center Honor. Mitchell returned to live performance with an unannounced show at the June 2022 Newport Folk Festival and has made several other appearances since, including headlining shows in 2023 and 2024.

Born Roberta Joan Anderson on November 7, 1943, in Fort Macleod, Alberta, Mitchell is the daughter of Myrtle Marguerite (née McKee) and William Andrew Anderson. Her mother's ancestors were Scottish and Irish; her father was from a Norwegian family that may have had some Sámi ancestry. Her mother was a teacher. Her father was a Royal Canadian Air Force flight lieutenant who instructed new pilots at RCAF Station Fort Macleod. During World War II, she moved with her parents to various bases in western Canada. After the war ended, her father worked as a grocer and her family moved to Saskatchewan, living in Maidstone and North Battleford. She later sang about her small-town upbringing in several of her songs, including "Song for Sharon".

Mitchell contracted polio at age nine and was hospitalized for weeks. She also started smoking that year, but denies that smoking has affected her voice.

She moved with her family to Saskatoon, which she considers her hometown, at age 11. Mitchell struggled at school; her main interest was painting. During this time she briefly studied classical piano. She focused on her creative talent and considered a singing or dancing career for the first time. One unconventional teacher, Arthur Kratzmann, made an impact on her, stimulating her to write poetry; her first album includes a dedication to him. She dropped out of school in grade 12 (resuming her studies later) and hung out downtown with a rowdy set until she decided that she was getting too close to the criminal world.

Mitchell wanted to play the guitar, but as her mother associated the instrument with country music and disapproved of its hillbilly associations, she initially settled for the ukulele. Eventually she taught herself guitar from a Pete Seeger songbook. Polio had weakened her left hand, so she devised alternative tunings to compensate; she later used these tunings to create nonstandard approaches to harmony and structure in her songwriting.