* CommonKnowledge:
** As noted on the main page, this was ''not'' the first appearance of Mickey (or {{WesternAnimation/Pete}}, for that matter). It is also a very common mistake in animation history that this short was the first sound cartoon, when those [[OlderThanTheyThink existed as early as 1924]] (and [[Creator/TerryToons Paul Terry]] had taken a shot at the sound cartoon called ''Dinnertime'' just a month before ''Willie'' was released).
** Pertaining to the plotline, Mickey isn't actually the Steamboat's helmsman. During the iconic opener, the ship's rudder is locked and Mickey is actually goofing off by being up at the wheel in the first place. His real job is to swab the deck.
* CrossesTheLineTwice: Animal abuse shouldn't be this funny.
* EarWorm: Mickey's whistle at the beginning.
* IAmNotShazam: Willie is the name of the Steamboat, but some people think that it's Mickey's name, via EarlyInstallmentWeirdness.
* NewerThanTheyThink: Though not by much. Few realize that ''Plane Crazy'' was made first.
* OlderThanTheyThink: As attested on the main page and above, Steamboat Willie was not even ''close'' to being the first sound cartoon, which [[Creator/FleischerStudios Max Fleischer]] had been doing as early as 1924 with his ''Song-Cartunes'' series, and Paul Terry had created his own sound film, "Dinnertime", just a month before Willie was released.
* SignatureScene: The first shot of Mickey piloting the boat is one of the most iconic pieces of animation in the history of animation. Disney even incorporates it into their opening logos of their newest animated features.
* ToughActToFollow: An often forgotten tidbit is that this short originally preceded a film called ''Gang War''. Now, animated shorts preceding movies was nothing new back then, in fact it was very common practice, but this short just so happened to be such a groundbreaking achievement that it largely overshadowed the film that followed it. In fact, ''Gang War'' ended up going forgotten enough that it now counts as a lost film (as in, ''no surviving copies of it are known to exist''), where ''Steamboat Willie'' continues to reign as perhaps the second biggest turning point in Disney's history (behind ''Disney/SnowWhiteAndTheSevenDwarfs'').
* WeirdAlEffect:
** The title is supposed to be a parody of the Creator/BusterKeaton film ''Film/SteamboatBillJr.''
** Not only that, but the BGM at the beginning of the cartoon was "Steamboat Bill", the song that the film was named after. The tune that Mickey was whistling was actually the chorus to the song.