Heather Louise McCartney was born Heather Louise See in Tucson, Arizona on December 31,1962. She is the daughter of Linda McCartney and her first husband John Melvin See Jr. When Heather was only one year old, her parents divorced. She then accompanied her mother to New York City, where Linda developed a career in photography and became a top-notch celebrity photographer. In 1967, Linda met Paul McCartney and the two became friends. After Paul split from his fiancee, actress Jane Asher, he invited Linda and Heather to move into his London home. Paul and Linda married on March 12, 1969, and Paul adopted Heather.

In 1977, Heather discovered London's punk-rock scene, which spurred her family's move to Sussex, England. In the 1980s she reconnected with her biological father and explored the American Southwest, where he lived. She later became a pottery designer. On April 17, 1998, her mother Linda died after a three-year battle with breast cancer; in February 2000 Heather suffered another sad loss when her biological father committed suicide.

These days, Heather keeps a low profile and continues to work on her pottery, for which she is famous in England.