As a journalist she has written for a number of British papers, including The Times, The Guardian and the Telegraph. She has written historical biographies as well as fiction, and has contributed to television documentaries.
Gristwood's historical biography, Arbella: England's Lost Queen is about Lady Arbella Stuart, an English noblewoman who was considered a possible successor to Elizabeth I. In a review in The Times, Kevin Sharpe wrote, "Sarah Gristwood presents a powerful story of the dynastic insecurity of the Tudors and Stuarts, and of the vulnerability of Elizabeth and James to foreign and domestic intrigues."
- Arbella: England's Lost Queen (2005). Houghton Mifflin. ISBN 9780618341337
- Elizabeth and Leicester: The Truth about the Virgin Queen and the Man She Loved (2008). Penguin Books. ISBN 9780143114499
- Blood Sisters: The Women Behind the Wars of the Roses (2012). Harper Press. ISBN 9780007309290
- Game of Queens: The Women Who Made Sixteenth-Century Europe (2016). Basic Books. ISBN 9780465096787
- The Story of Beatrix Potter (2016) United Kingdom: Pavilion Books. ISBN 9781909881808
- "Sarah Gristwood". HarperCollins. Retrieved 16 February 2018.
- "Sarah Gristwood". Retrieved 16 February 2018.
- Sharpe, Kevin (2 February 2003). "Review: Biography: Arbella, England's Lost Queen by Sarah Gristwood". The Sunday times. Retrieved 16 February 2018.
- Dunant, Sarah (2 December 2016). "Women of Thrones". New York Times. Retrieved 16 February 2008.
- "Sarah Gristwood". IMDb. Retrieved 17 February 2018.
- "Skeletons in the Closet". Evening Standard. 6 March 2003. Retrieved 16 February 2018.