Elyne Mitchell was born in Melbourne, but travelled with her family to Europe before the outbreak of World War I. Her father was General Sir Harry Chauvel, commander of the Desert Mounted Troops which became famous for their cavalry charge of Beersheeba. After marrying the lawyer and skier Tom Mitchell, she learned to ski and won the Canadian downhill skiing championship in 1938. The couple had moved to Towong in the Snowy Mountains in 1935 and often explored the mountains on foot, ski and horseback. Mitchell wrote about these trips in her first book, Australia's Alps (1942), and remained a strong advocate for the area throughout her life.
Mitchell is best-known for the series of children's books that began with The Silver Brumby (1958). Inspired by her daughter's desire for more interesting books, the novel was first rejected by several publishers before becoming a best-seller upon publication. The book was commended by the Children's Book Council and became the introduction to a twelve book series, the last appearing in 1999. Mitchell's other writing includes a history of the Australian Light Horse, autobiography, adult novels, books on the Australian Alps and discussions on environmental issues.
Mitchell remained very active throughout the 1990s, but after an operation for a brain tumour she moved from her mountain home to nearby Corryong to live-in care. She died in Corryong in 2002.