Margaret Lacey (1910- October 4, 1988) was a Welsh actress.
She appeared in over 30 films between 1957 and 1985 mostly playing a sweet old lady or motherly figure in minor roles. She is perhaps best remembered internationally for starring in the 1971 James Bond film Diamonds Are Forever in which she played a seemingly innocent Christian school teacher, Mrs Whistler, who smuggled diamonds in her bible for the henchmen Wint and Kidd. In the film she is later founded murdered and her body recovered out of an Amsterdam canal.