* BreakthroughHit: The film's $69.8 million gross made it the Disney studios' first real live action hit since ''Film/TheLoveBug'' in 1969, and established Touchstone Pictures as the go-to brand for live action Disney movies in the 1980s and through the 1990s.
* {{Bowdlerization}}: On the UK's Cinemagic channel, the store clerk's line, "My daughter's lucky. She's anorexic," was edited to remove "She's anorexic."
* DuelingMovies: Nearly every major Hollywood studio rejected producer Brian Grazer's pitch for ''Splash'' in order to avoid competition with another film project titled ''Mermaid'' which also had the story of a man falling in love with a mermaid. Unlike ''Splash'', many big names were attached to the project - Herbert Ross was going to direct the film, Ray Stark was going to produce it, Robert Towne (of ''Chinatown'' fame) was going to write the screenplay, Jessica Lange was going to play the titular mermaid, and Creator/WarrenBeatty was going to play the male lead.
** In order to persuade the Disney company into green-lighting ''Splash'', Grazer told the studio that he would make their film "faster, cheaper, and better" than "Mermaid".
** However, due to a possible "actors strike" delaying progress, the "Mermaid" project was ''declared dead''.
* TheRedStapler: "Madison" as a first name was virtually unheard-of when this movie came out. (During the first half of the 20th Century, it was in the top 1000 boys' names.) Thanks to ''Splash'', it has been in the [[https://www.ssa.gov/oact/babynames/ top ten girls' names for almost two decades]]. It spent two years in second place, before receding to ninth place in 2012, 2013, and 2014. It finally inched out of the top ten in 2015, making 11th.
* StarMakingRole:
** Creator/DarylHannah
** Creator/TomHanks. He was not unknown, but this was the first sign that he could not only make the transition from television, but outright headline a movie.
* WhatCouldHaveBeen: The scene where a TV show makes Madison upset and Allen explains the TV show is fictional and didn't really happen was originally going to be part of a BrickJoke where Madison later watches a real life plane crash on the news and laughs.
** Bruce Jay Friedman's original script had the film mostly take place ''underwater'', in which the audience would get to see Madison and the merpeople who live there. However, Ron Howard suggested that it would be easier (for logistical reasons) to have the story take place on land rather than under the sea, so Lowell Ganz and Babaloo Mandel were hired to do rewrites, with the focus now being more on Allen and his relationship with his "mermaid girlfriend" Madison.
** The original ending [[spoiler: didn't have Allen jumping in the water to be with Madison]]. In the DVD audio commentary, Ron Howard said the ending was changed ''at the suggestion of his wife, Brian Grazer's wife, and the wives of Lowell Ganz and Babaloo Mandel'' (in fact, Babaloo's wife went as far as saying to Babaloo, "If he doesn't go, you go!").
** The "sea hag" sequence in which Madison would learn about the "rules" was filmed (brief footage of it can be seen in the "making of" documentary on the DVD), but it was cut due to test audiences finding it [[MoodWhiplash "too foreboding"]], as well as being too difficult to film, since itís underwater and a lot of acting is involved.