Hideo Kojima had requested that Metal Gear Solid's Solid Snake be in the game, but due to time constraints he couldn't be added to the game's roster. Sonic the Hedgehog also nearly made it into the game. Sonic's creator Yuji Naka stated that Sonic was going to be in Melee, but he also was cut due to time constraints. Both characters later made it into the sequel, Super Smash Bros. Brawl.

In early versions of the game, the Princess Daisy trophy contains a third eye beneath her hair if viewed at the right angle. In fact, there are many hidden eyes all over her head, but this is the only abnormal eye that can be seen in normal play.

The main character of the game Devil World, Tamagon, appeared as a trophy in the Japanese version of Super Smash Bros. Melee. Tamagon was removed in the American version of the game but the trophy can still be found with Action Replay, complete with a translated description. Stranger still, the Tamagon trophy was removed outright from the European version of the game and cannot even be found with a cheat device, despite the fact that Devil World was released in European countries.

There are many Regional differences between the Japanese and U.S. versions of Super Smash Bros. Melee. They include name changes (Jigglypuff is named Purin and Bowser is named Koopa in the Japanese version), event names ("Time for a Check Up" is "Don't Hog The Spotlight, Bro" in Japan), and different names for items (Bob-Omb is Bomb Soldier in Japan).

Unused character intro loading screens for All-Star mode can be found by using the game's debug mode. They were most likely removed because the player may fight multiple opponents simultaneously in some rounds.

The Letters "2L84ME" (too late for me) are printed on the back of the Barrel Cannon Trophy.

An Excitebike racer from the game Excitebike, Balloon Fighter from the game Balloon Fight, Urban Champion from Urban Champion and Bubbles from Clu Clu Land were considered for characters that could be used to represent the NES era of Nintendo in the game, but Sakurai decided that the Ice Climbers would be far more fitting as fighters.

There is a glitch that allows the game to advance to the stage selection screen without properly configuring the match. Any player that does not select a character will be set to Master Hand as a default. However, Master Hand will only respond to controller port 3.

There's a reflection of the 'Yoshi's Island' stage on the Metal Mario trophy.

In Luigi's "Break the Targets" room, the small square in the middle of the stage, which he begins standing on, is actually a Nintendo Gamecube.

In Captain Falcon's "break the target" room, a picture of dolphins can be found on the left-most wall. This may be a reference to the original codename of the Gamecube, which was "The Dolphin".

Luigi's voice is just a pitch-altered version of Mario's.

The Metroid trophy has an image reflecting off of its shell. The image is of the space station from the beginning of Super Metroid.

Captain Falcons' red costume was originally planned to say "Hell Hawk" on the back.

The Pokemon, Ditto, was meant to be a possible helper when a Pokeball was thrown. He was supposed to transform into the player that threw the ball and would help fight. However, there were problems with its programming and it was removed. By using an action replay, Ditto can be put back into the game, but he is lacking his "transform" ability. Instead, all it does is say "Meta!" (it's Japanese name being Metamon) and disappears. Anyone who runs into it is dealt 7-8% damage.

On the description of the Meta Knight trophy, it states that he made his debut in Kirby Super Star. This however is incorrect, as his first appearance was in Kirby's Adventure, four games before Kirby Super Star was released.

The original boxart did not feature Link or Pikachu, and instead featured Mario being attacked by Bowser's Fire Breath move.

The Great Fox trophy says that it first appeared in Star Fox, but its debut was actually in Star Fox 64.

The Metroid trophies claim that the original Metroid was released in 1989 (8/89), but it was released in 1986.

Early English releases of the game changed the "Magnum Killer" (The Japanese name for Banzai Bill) trophy to "Bullet Bill", accordingly changing the game data to "Super Mario Bros. 10/85". The description acknowledges that that all the "Bullet Bills" in Melee are the rarer, extra-large variety, yet it seems the translators were unaware that those are called Banzai Bill. Later English releases fixed the name and description, but did not change the game data back to Super Mario World.