McLachlan was born in Halifax, Nova Scotia, Canada. When she was four years old, her idol was Joan Baez. As a child, she took voice lessons, along with studies in classical piano and guitar. When she was just seventeen years old, she fronted a new wave band, October Game. Her high school yearbook claimed that she was "destined to become a famous rock star."
In 1988, she was one of the first artists signed by the independent Canadian record label Nettwerk. The signing prompted McLachlan to move to Vancouver, British Columbia. There she recorded the first of her albums, Touch, in 1988, which received both critical and commercial success. Several albums followed in later years, with McLachlan writing many of the songs she recorded. On February 7, 1997 she married Ashwin Sood, her longtime drummer in Negril, Jamaica. That same year, Lilith Fair debuted in Vancouver. It ran for three years, after which McLachlan began an extended period away from recording or touring. She did, however, participate in the 2002 British Columbia Cancer Foundation Benefit Concert in memory of cancer victim Michele Bourbonnais. She participated along with four other premiere Canadian artists: Bryan Adams, Jann Arden, Barenaked Ladies, and Chantal Kreviazuk.
Known for the emotional sound of her ballads, some of her popular songs include Angel, Building a Mystery, Adia, Possession, and I Will Remember You. Her most popular album was Surfacing, for which she won two Grammy Awards and four Juno Awards. Through her career, she has also received many other awards. Primarily in recognition of her efforts in launching Lilith Fair, she was presented with the Elizabeth Cady Stanton Visionary Award for advancing the careers of women in music. In 1999, she was appointed as an Officer of the Order of Canada in recognition of her successful recording career, her role in Lilith Fair, and the charitable donations she made to women's shelters across Canada. Sarah gave birth to a daughter, India Ann Sushill Sood, on April 6, 2002 in Vancouver, British Columbia, Canada.