Mary Trueblood is assistant to British Secret Service section chief John Strangways in the Ian Fleming novel Dr. No and its 1962 film adaptation. In the latter she is played by the late actress Dolores Keator.
As in the novel, Mary Trueblood was secretary to John Strangways, operating the British Secret Service station in Jamaica. Unaware that Strangways has been murdered, she proceeds to make contact with London for their scheduled transmission. Hearing a noise, she proceeds to investigate, only to find Strangways' killers, the Three Blind Mice breaking into the house. As she turns, she finds one of the men at the window behind her and is shot in the breast. As they take her body out, they carefully remove all the Service's files relating to Crab Key and Dr. No.
- Dr. No was Dolores Keator's only onscreen role in the film business. She owned the building in Jamaica used for filming as Strangways' house.
- Mary was the first Bond girl ever to appear onscreen in the official EON Bond films. Although she isn't technically an official Bond girl, as her part is minor and she never had any romances with Bond that we know of.