Oluwunmi Mosaku (born 1986) is a Nigerian-born British actress. She is known for her roles as Joy in the BBC Two miniseries Moses Jones (2009) and Holly Lawson in the ITV series Vera (2011–2012). She won the BAFTA TV Award for Best Supporting Actress for her role as Gloria Taylor in the TV film Damilola, Our Loved Boy (2016). In 2019, she starred in the fifth series of Luther. In 2020, she starred as Ruby Baptiste in HBO's Lovecraft Country, and starting in 2021, she starred as Hunter B-15 in the Marvel Cinematic Universe (MCU) television series Loki and reprised the role in the 2024 film Deadpool & Wolverine.
She was nominated for the BAFTA for Best Actress and won the BIFA for Best Performance by an Actress in a British Independent Film for her role as Rial in the film His House (2020).
Mosaku was born in Zaria, Nigeria, and subsequently emigrated to Manchester, England, when she was one year old. She attended Trinity Church of England High School and Xaverian Sixth Form College. She also sang for eleven years in the Manchester Girls Choir. Her parents were both professors in Nigeria. Her mother started a business and her father ended up returning to Nigeria. Mosaku studied acting at the Royal Academy of Dramatic Art, graduating in 2007, with a BA in Acting Degree (H Level).