Sarah Stephens was born 7 June 1990 in Lancashire, England. Her parents are Australian and she has three younger brothers. She grew up in Sydney.
As the winner of Girlfriend magazine's Model Search, Stephens won a two-year contract with Chic Model Management and was later signed by Next Model Management in New York and Paris. Stephens has been on the covers of many magazines including Russh Australia, Frankie magazine, Madison, GQ, French Revue de Modes, and Eurowoman.
She has a role in the movie Solitary Man with Michael Douglas and Danny DeVito.
In 2011, she was signed as a face of the Australian swimwear label Seafolly.
In 2015, she played the young witch in the horror film The Witch.
In 2006, at the age of 16, Stephens won the nationwide Girlfriend Magazine Model search.