According to Brian Cosgrove, when Roald Dahl saw his first screening of the film in Soho, when it ended and the lights went up, Dahl stood up and clapped.
When Roald Dahl wrote "The BFG", he named the lead child character Sophie, after his granddaughter, actress and model Sophie Dahl.
David Jason considered the film brilliant. He named his daughter Sophie Mae because the name has extra resonance for him after doing the film, and the two sounded nice when put together.
The boy who dreams that he becomes invisible has a Danger Mouse (1981) poster above his bed, which also starred David Jason and animated by Cosgrove Hall Films.