Bannerman was born in Edinburgh. Because women were not admitted into British universities, she sat external examinations set by the University of St. Andrews, attaining the qualification of Lady Literate in Arts (LLA).
Bannerman wrote about India. The illustrations and settings of her books demonstrate that the children she writes about are south Indian or Tamil. For instance, Little Black Sambo has ghee, tigers, and bazaar, Story of Little Black Mingo has jungle, mugger (a kind of crocodile), dhobi, and mongoose, Little Black Quasha has bazaar and tigers, and Story of Little Black Quibba has mangoes and elephants.
Bannerman lived much of her life in India, where her husband William Bannerman was an officer in the Indian Medical Service, including 32 years in Madras.
Because the name Sambo has come to be seen as a slur on people of colour, the books have often been blacklisted or censored. This prompted a new version co-authored by Fred Marcellino called The Story of Little Babaji, with the names of the main characters changed. Earlier, in 1976, Platt & Munk Publishers had issued a version of Little Black Sambo with the parents' names identifiably Indian, and the picturesque illustrations altered to indicate decidedly Indian clothing.
- The Story of Little Babaji (with Fred Marcellino), 1996 (Little Black Sambo with more politically correct names), ISBN 0-06-205064-8
- The Story of Little Black Sambo, 1899
- Story of Little Black Mingo, 1901
- Story of Little Black Quibba, 1902
- Little Degchie-Head: An Awful Warning to Bad Babas, 1903
- Little Kettle-Head, 1904
- Pat and the Spider, 1905
- The Teasing Monkey, 1907
- Little Black Quasha, 1908
- Story of Little Black Bobtail, 1909
- Sambo and the Twins, 1936
- Little White Squibba, 1965 (a rewrite of Little Black Sambo with a white girl as heroine). Elizabeth Hay (1981) wrote that Helen's daughter Day completed the Squibba book from scribbles Helen had written down. 
- (Hay 1981, pp. 152-153)
- Hay, Elizabeth (1981), Sambo Sahib : the story of Little Black Sambo and Helen Bannerman (1st ed.), Edinburgh: Paul Harris Publishing, ISBN 0-904505-91-X
- Works by Helen Bannerman at Project Gutenberg
- Helen Bannerman in SterlingTimes
- The Story of Little Black Sambo in SterlingTimes