Margaret Tarrant was born in Battersea, south London. Her father Percy Tarrant was a well-known landscape painter. She attended Clapham High School and studied at the Clapham School of Art, Heatherley’s School of Art, and Guildford School of Art. She began her career by designing cards and calendars. In 1908, at age 20, she received a commission to illustrate The Water Babies by Charles Kingsley. Two years later, she illustrated Fairy Stories from Hans Christian Andersen and the Contes of Charles Perrault; she went on to illustrate many other works for children, many of them now considered classics. She also exhibited her art at the Royal Academy and the Walker Royal Society of Artists.
Many of her paintings contained characteristics of the Arts and Crafts movement and the Art Nouveau style she admired. She was associated with the Medici Society for many years, and many of her best postcards, calendars, and children's books were published by that organization. Medici re-published six Fairy books in 2002 for the first time in 80 years.
Her work continues to charm and delight readers and collectors.