She is the daughter of British author Roald Dahl and American actress Patricia Neal. Her relationship with actor Julian Holloway produced one daughter, model and author Sophie Dahl. She married businessman James Kelly and had two children, Clover and Luke. She then married businessman Patrick Donovan and had a son, Ned.
After a brief stint as an actress during the 1970s, Tessa Dahl became a prolific author of a best-selling novel "Working For Love" and popular storybooks for children. Her book "Gwenda and the Animals" won The Friends of The Earth Best Children's Book of the Year. In addition, she has written extensively for the London Sunday Times, The Daily Telegraph, the Daily Mail, and is a contributing editor to the women's glossy magazine Tatler.