Winifred Gill was born in 1891, the fifth of seven children of a Quaker family in Guildford. Her father Henry Gill part owned and ran a local ironmongers. She was educated at Guildford High School, and would have liked to attend university, but the family didn't have the money to send her there. She was later able to attend the Slade School of Fine Art for a year.uildford, Gill was taken on by his sister Joan Fry as a secretary, assisting in her philanthropic work. Roger Fry encouraged Gill in her artwork and she was one of the early members of the Omega Workshops, which was established in 1913. There she worked alongside the likes of Vanessa Bell, Wyndham Lewis and Duncan Grant. Like most female employees at Omega, she was mostly involved in translating design onto items rather than in the creative process (e.g. needlework, drawing up technical drawings for rugs, decorating pottery and lampshades, etc.), but she was able to do her own original art. She created marionettes, some of her work was exhibited at the second Grafton Group exhibition in October 1913, and she and Vanessa Bell decorated the 'Omega Nursery'. Gill was a key figure in the administration of Omega; she ran the business for a brief period at the beginning of the First World War, when the business manager Charles Robinson joined the Friends' War Victims Relief Commission. A new business manager (a former employee of Gill's father) was appointed, but Gill remained a 'connecting link' between the artists and the administration of the workshops until it closed in 1919.

Years later, Roger Fry's daughter Pamela Diamand contacted Winifred Gill, as she felt that her father's work should be rediscovered. The result of this was a correspondence between Gill and Duncan Grant, the only other surviving member of the Omega Workshops, with Gill using her reminiscences of the Workshops to jog Grant's memory.

After leaving Omega, Gill briefly worked in the Guildford registry office, and for three years was Art Mistress at Howell's School in Llandaff. Soon after that, she became involved with the University Settlement Movement. She was a resident at the Bristol University Settlement from 1923, where she taught arts and crafts, and worked alongside people including Hilda Jennings, Marian Fry Pease and Hilda Cashmore. Hilda Cashmore was appointed warden of the Manchester University Settlement in 1926, and Gill went to Manchester with her. Again, she was involved in teaching arts and crafts, and when L.S. Lowry came to Ancoats to exhibit some of his work in 1930, Gill suggested places that would make good subjects for drawing.

While at the Bristol University Settlement, she and Hilda Jennings were commissioned to do audience research about radio broadcasting for the BBC. Gill worked in the Listener Research Department of the BBC from 1942 until she retired in 1951. After that, she gave broadcast talks for the BBC, including for 'Woman's Hour', and 'Lift Up Your Hearts', and also gave puppet shows semi-professionally.

Winifred Gill's other interests and activities included writing (she had poems published in anthologies, including A Faggot of Verse and Poems by Heptagon), and archaeology (she took part in the Meare Lake Village dig in 1927).

For the last 27 years of her life, Gill lived with her niece Dr Margaret Bennett in East London. She died in 1981.