Sarah Ellis was born and brought up in Vancouver, British Columbia. The energetic and imaginative youngest of three, Ellis liked to tell stories and play imaginary games. She learned to read at a young age as reading was a family activity in Ellis' home. Her parents often read stories aloud to Ellis and her brothers and encouraged her love of literature by giving her books.
In addition to writing Ellis also had a diverse range of other interests, and like Polly, the protagonist in Pick-Up Sticks, Ellis played the French horn. Because of her wide range of interests, Ellis did not envision a career for herself as a professional writer, although others did.
In 1973, after completing a diverse Bachelors of Arts program at the University of British Columbia, Ellis still did not know what career path she wished to pursue. When a friend decided to go to the UBC's Library School she decided to attend as well. She greatly enjoyed her studies and planned to become a professional librarian. After working for some time as librarian, Ellis decided to pursue a Masters degree in children's literature at Simmons College, in Boston.
While studying, she began writing because her instructors encouraged writing as a part of the program. When she completed her degree in 1980, she returned to her work as a librarian for the children's collection at the North Vancouver District Library.
Sarah Ellis' objective is not to write books for children, but rather to write books about children. She says she writes about the adolescent years because she is interested in the period of transition from child to adult and is driven to explore it in her writing. She often uses her own experiences and memories as a guide to writing about adolescent characters. She also uses her personal memories of growing up, her family and her own life as inspiration for her work.
Her first book, The Baby Project, was awarded the Sheila A. Egoff Children's Book Prize in 1987 and Pick-up Sticks won the Governor General's Literary Award in 1991. The Canadian Author's Association recognised Sarah's contribution to the field of children's literature by awarding her the Vicky Metcalf Award.