Shelagh McDonald (born 1948) is a Scottish folk singer, song-writer and guitarist who released two albums before her abrupt and mysterious disappearance in 1971. On her albums, she was backed up by many notables within the English folk-rock scene, including Richard Thompson, Dave Mattacks, Danny Thompson, Keith Tippett, Keith Christmas, the Fotheringay rhythm section, as well as Ian Whiteman, Roger Powell and Michael Evans, then members of Mighty Baby.

On 23 June 2005, by which time McDonald's albums had been reissued on CD, an article by Charles Donovan appeared in The Independent, the first high profile piece about McDonald's disappearance. This prompted copycat features in local papers, the Glasgow Herald and the Scottish Daily Mail. It was the latter of these that caught the eye of McDonald herself. In November 2005, McDonald turned up in the offices of the Scottish Daily Mail and told them her story. She retreated from public life after a bad LSD trip left her paranoid and hallucinating, with a ruined voice. Living with her parents and working privately in Edinburgh, she met and married bookseller Gordon Farquhar; together, they lived a nomadic lifestyle in north Britain, living on welfare benefits and moving from house to house, and later tent to tent.