Muriel Denison was born Jessie Muriel Goggin in Winnipeg, Manitoba, Canada. She was educated at Havergal College and the Royal Conservatory of Music in Toronto. In 1926, she married Merrill Denison, an author and playwright.
She is best known for the "Susannah" series of children's books, set in the years 1896-1900 and featuring Susannah Winston, an adventurous young girl who goes from ages 9 to 13. The first book, Susannah of the Mounties (originally known as Susannah: A Little Girl of the Mounties, 1936), was the inspiration for a Hollywood adaptation starring Shirley Temple. Muriel
Denison also wrote under the pseudonym Frances Newton for articles in magazines such as This Week, Reader's Digest, and McCall's.