Q. I am writing a novella. One of my characters is a scientist. I do not know whether to write her name as Doctor Quimby or Dr. Quimby in narration or dialogue.
A. We get some version of this question a lot. The thread they all seem to share is a worry that an abbreviation (or more often a number) won’t look natural in dialogue. But though it’s true that people don’t normally speak an abbreviation as it’s spelled, the word Doctor is almost always abbreviated as a title before a name (regardless of the type of doctor). Plus, any reader (including text-to-speech applications) should know that Dr. is pronounced Doctor.
So unless you prefer the spelled-out form—there’s nothing wrong with spelling out Doctor—you can safely use the familiar abbreviation in all contexts, including dialogue. In other words, you can model your usage on the novella originally titled Strange Case of Dr. Jekyll and Mr. Hyde (by Robert Louis Stevenson; the abbreviations Dr. and Mr. appeared in both the title and text of the 1886 London first edition—and featured periods in the text but not on the title page or cover) rather than on Doctor Zhivago (the novel by Boris Pasternak, where Doctor in the title translates the unabbreviated Russian Доктор).
For more information about spelling out abbreviations and numbers in dialogue, see CMOS 12.51.