Leslie Dilley (January 11, 1941 — May 20, 2025) was a Welsh art director and production designer. During his career from the 1970s to 2000s, he won the Academy Award for Best Art Direction twice for Star Wars (1977) and Raiders of the Lost Ark (1981). Dilley received additional Best Art Direction nominations for Alien (1979), The Empire Strikes Back (1980), and The Abyss (1989). Apart from art direction, Dilley was a production designer for The Exorcist III (1990), Casper (1995), and Son of the Mask (2005).

In 1941, Dilley was born in Rhondda Valley, South Wales. Growing up, Dilley and his family moved to London and lived in Wembley Park. For his post-secondary education, Dilley studied architecture at Willesden Technical College. While working as an apprentice plasterer during college, Dilley was encouraged by a classmate to apply at Pinewood Studios. After Pinewood told him there were no open positions available, Dilley completed a five year plastering apprenticeship at the Associated British Picture Corporation.