Ruby Leilani N. Ashbourne Serkis (born October 11, 1998) is an English actress.

Ashbourne Serkis was born in Hackney, East London, to actors Andy Serkis and Lorraine Ashbourne and grew up in North London with her younger brothers Sonny and Louis. She attended the City of London School for Girls.

Ashbourne Serkis began her career with small cameos before landing a titular role in the 2015 BBC One television film adaptation of Laurie Lee's memoir Cider with Rosie, for which she received critical acclaim. The following year, she portrayed a young version of Susan Lynch's character in the Channel 4 miniseries National Treasure.

Ashbourne Serkis returned to television in 2020 as Lavinia in the Netflix fantasy series The Letter for the King, an English-language adaptation of the classic Dutch book by Tonke Dragt. She appeared opposite Alice Englert in the first episode of the crime drama The Serpent. She and her brother Sonny portrayed siblings in the film La Cha Cha. Although the film received mixed reviews, Ashbourne Serkis' performance was praised. In November 2021, Ashbourne Serkis joined the cast of the upcoming Apple TV+ film The Greatest Beer Run Ever.