Helen Isobel Mansfield Ramsey Stratton was a British artist and book illustrator.

Stratton was born in Nowganj, Bundelkhand, Madhya Pradesh, India on 5 April 1867, the daughter of a surgeon in the Indian military service John Proudfoot Stratton and Georgina Anne Anderson. Soon after Helen's birth, and following her father's retirement, the family moved to England, settling in Bath. By 1891 Helen was in Kensington, London to attend art school, where she became a follower of Art Nouveau in the style of the Glasgow School of Art. For many years she lived and worked as a book illustrator and painter in Kensington with her widowed mother and siblings. Stratton remained unmarried and in the 1930s she returned to Bath, living at The Bungalow, Widcombe Hill. She died on 4 June 1961, age 95, at Cran Hill Nursing Home, Weston.

From 1896, Stratton became well known for bold and imaginative pen and ink illustrations to classic tales. Her first success was illustrating Norman Gale's Songs for Little People, of which The Bookseller wrote in 1896 "Miss Stratton has headed, tailed and bordered the verses with a series of exquisitely pictured fancies". In 1898, she drew 167 illustrations for Walter Douglas Campbell's Beyond the Border. A year later, she reached the peak of her illustration career with upwards of four hundred drawings for a finely crafted art nouveau quarto edition of The Fairy Tales of Hans Christian Andersen, published by George Newnes. In the same year, she collaborated with William Heath Robinson and three other illustrators (A D McCormick, A L Davis and A E Norbury) to create hundreds of illustrations for The Arabian Nights Entertainments, initially published in sections, then later in a large quarto edition. Although initially noted for her black and white illustrations, she also illustrated in watercolour for works such as H.C. Herbertson's Heroic Legends (1908) and Jean Lang's A Book of Myths (1915). Her work for The Princess and the Goblin by George MacDonald and its sequel The Princess and Curdie (1912) were particularly popular and have been frequently reprinted.