Janet Macdonald Aitken CBE (1873–1941) was a Scottish portrait and landscape painter.

[2] Returning to Glasgow, after some time in Spain, she became part of the circle of artists associated with Charles Rennie Mackintosh and a member of the informal group of artists known as "The Immortals", which also included Agnes Raeburn, Margaret Macdonald Mackintosh, Jessie Newbery, Ruby Pickering, Katharine Cameron, Jessie Keppie and Frances McNair.

[5] Aitken often painted urban scenes and views of old buildings, working in both oils and watercolours.

Several of her black and white sketches of Glasgow street scenes were reproduced as postcards.

[6] A memorial exhibition to her, and to Kate Wylie and Elma Story, was held by the Glasgow Society of Lady Artists in 1942.