Olivia Jane Grierson (née Chenery; born 11 March 1989) is an English actress and environmental advocate. Her films include Brotherhood (2016) and 10x10 (2018). On television, she is known for her roles in the BBC series Queens: The Virgin and the Martyr (2017) and the Sky One series Bulletproof (2020–2021).

Chenery was born in the South London Borough of Croydon to parents Emma and Julian. She has two sisters. She joined the National Youth Theatre and went on to study at the London School of Musical Theatre, graduating in 2010.

Chenery made her television debut as a Plantagenet Princess in the 2013 HBO and BBC Two comedy Family Tree and her feature film debut as Sandy in the 2014 science fiction thriller The Anomaly. This was followed in 2015 by roles in the film Legacy and as a witch in the second season of the Showtime and Sky Atlantic horror series Penny Dreadful.

Chenery had lead roles in the 2016 and 2018 films Brotherhood as Sariya and 10x10 as Alana Lewis, respectively. In 2017, she starred as Mary, Queen of Scots in the British-Spanish historical drama Queens: The Virgin and the Martyr, made for Televisión Española and the BBC.

In 2020, Chenery joined the main cast of the Sky One police procedural Bulletproof for its second series as Scarlett "Scooch" Hailton. She had a recurring role as Holly in the 2021 Netflix science fiction series The One.

Chenery appeared in the 2022 and 2023 films Prizefighter: The Life of Jem Belcher and Jericho Ridge. In the 2023 local elections, Chenery (under her married name Olivia Grierson) unsuccessfully stood to represent Oxted South for the Green Party on Tandridge District Council.