Gwyneth Strong (born 2 December 1959) is an English actress. She is best known for her role in the BBC sitcom Only Fools and Horses as Cassandra, the love interest and, later, wife of Rodney (Nicholas Lyndhurst).

Strong's first acting appearance was in the Royal Court Theatre's production Live Like Pigs, when she was eleven. In 1973, whilst a pupil at Holland Park School, she appeared in the horror film Nothing But the Night as Mary Valley, and she was a regular in the children's TV series The Flockton Flyer between 1977 and 1979, as Jan Carter. As well as her prominent role in the later series of Only Fools and Horses, she has appeared in the "Observation" segment about Detective Samantha Smith made for the 1990 series of The Krypton Factor, the two-part drama serial The Missing Postman as WPC Rachel McMahon, the BBC drama Real Women from 1997 to 1998, as Hetty in ITV's Lucy Sullivan Is Getting Married (1999), and in BBC drama Casualty in 2013 as Jim Brodie's wife, Elizabeth.