"Mademoiselle Fifi" is a short story by French writer Guy de Maupassant, published in 1882. The story is set during the Franco-Prussian War and explores themes of class barriers, contrasts between the French and German participants, and the pointlessness of the war.

The story takes place in Normandy in the winter of 1870, in a fictional chateau which is being used as a headquarters by Prussian officers. The main characters of the story are: the Major, a dignified and cultured German aristocrat; his Captain, a boorish and lecherous minor Prussian landowner; two lieutenants from the Prussian bourgeoisie; and the title character, a handsome but arrogant and extremely unpleasant German sub-lieutenant known to his comrades as "Mademoiselle Fifi" due to his effeminate manner.