Mary Trueblood (1925–1962) was a British woman who worked for MI6 as secretary to Jamaica station chief John Strangways. In 1962, a few minutes after Strangways was murdered by the Three Blind Mice, Trueblood contacted London for their scheduled transmission. Waiting for Strangways, Trueblood was ambushed and murdered by the Three Blind Mice as London was left in radio silence.
A key was taken from her corpse and used to open a file cabinet containing files on Dr. Julius No and Crab Key, which were both stolen. Trueblood's body was then taken away to be disposed of.