* ActingForTwo: Barrie Ingham voices both Basil and the unlucky Bartholomew.
* AwesomeDearBoy: Price on his role as Ratigan.
* DuelingMovies: With ''WesternAnimation/AnAmericanTail'', another animated movie about mice coming out the same year (though it didn't come out until a few months afterward). The Great Mouse Detective lost in the end, but that didn't mean it wasn't successful; in fact, it convinced Disney that its animation unit still had a future.
** The success of An American Tail probably helped convince Disney as well.
* ExecutiveMeddling: Largely averted, as Jeffery Katzenberg had little to no faith this movie would be any good. Most of his attention was spent on meddling with ''Disney/TheBlackCauldron'', which became a failure. Katzenberg did, however, demand the title of this film be changed from "Basil of Baker Street" to simply "The Great Mouse Detective". Two of the four directors have since said they've always hated the new title.
** However those directors may have had some solace in the title being changed to "Basil the Great Mouse Detective" is some countries, including Australia.
* HeyItsThatVoice:
** Sherlock Holmes is... [[BasilRathbone Sherlock Holmes!]]
** VincentPrice, a one-man RoguesGallery of villain voices, including Professor Ratigan. Also, Melissa Manchester as a showgirl!
** Hiram Flaversham is performed by Creator/AlanYoung in the same Scottish burr he used for [[WesternAnimation/DuckTales Scrooge McDuck]].
*** In Mexican Spanish, it's ''Fidget'' (the bat) who's Uncle Scrooge.
*** In Italian, it's ''Dr. Dawson''.
** Wayne Allwine (MickeyMouse himself) voices one of Ratigan's {{Mooks}}; to be precise, [[Disney/AliceInWonderland Bill the Lizard]].
** In Italian, Olivia would later become [[Franchise/StarWars Padme]]!
** In Japan, the voice of Fidget is also the voice of [[Franchise/SonicTheHedgehog Dr. Eggman]]! Even better, Ratigan is [[{{Disney/Aladdin}} Jafar]].
** [[CatsAreMean Felicia]] is voiced by [[ScoobyDoo Fred]] [[FrankWelker Jones]].
* WhatCouldHaveBeen: Music/{{Madonna}} was considered to voice Miss Kitty and perform the song "Let Me Be Good To You".
** This isn't as far-fetched as it may seem when one listens to Madonna's jazzy showtunes on the ''Film/DickTracy'' soundtrack.
** Olivia was originally planned to be older, acting as a potential love interest for Basil, but it was later decided she should be a child to make her more sympathetic.
** Creator/JohnCleese was the first choice to voice Basil.
** Ratigan's original design was [[LeanAndMean very thin and frail-looking]]. They changed it after Creator/VincentPrice was cast [[InkSuitActor to reflect Price's larger build]]. Glen Keane also says that he based it partially on then-head of the studio, Ron Miller, an ex-football player.
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