The Water Land theme was later used as the theme for the Fairy Fountain in the Legend of Zelda series.

For every 80,000 points you score, a matching card game will appear on the board. This is a chance to receive items such as coins and power-ups. There are only a total of Eight (8) different patterns.

Several of the Koopa Kids' names are parodies of various musical celebrities, most of whom were popular at the time of SMB3's production.

- Iggy Koopa is named after American rock singer Iggy Pop.
- Lemmy Koopa takes his name from Lemmy Kilmister, a British heavy metal artist best known from his work in the band Motörhead.
- Ludwig Von Koopa is named after 19th Century composer Ludwig van Beethoven, and shares his wild hairstyle.
- Morton Koopa Jr. is named after American pop and country singer Morton Downey Jr., now perhaps best known for his self-titled talk show. Morton Koopa Jr. also has a white face with a black star over his left eye, the trademark makeup of guitarist Paul Stanley from KISS.
- Roy Koopa is named after Roy Orbison, and both wear horn-rimmed sunglasses.
- Wendy O. Koopa is named after Wendy O. Williams, an American punk singer.

It's unclear who Larry Koopa is supposed to be based on, but he could be based on Larry Mullen Jr, the drummer for the band U2.

The fortress in World 1 was slightly changed from the Japanese version to make things a bit easier. The right wall in the spike hallway was originally farther away, and the door was under a spike.

The island with the castle in World 3 resembles Japan, with the castle being the location of Kyoto, Nintendo's headquarters.

The box art for the game shows images from earlier stages of the game's development. The image of word 1 has different paths when compared to the final version, and the second image doesn't represent anything seen in the game's final build.

It was once planned for Mario to have a power up that turned him into a Centaur. This isn't as outlandish as it seems; the Tanooki suit was also inspired by the legendary Tanuki.

The Koopalings were based on seven of the game's developers. They were all later named after musicians by the American localization team, as no distinct names were given in the Japanese version. It's also speculated the musical names were chosen because their scepters resemble microphones.

If you let a Chain Chomp tug on its chain 49 times, it will actually break free.

In a 1996 interview with Shigeru Miyamoto published in Super Mario 64's first Japanese strategy guides, he revealed that Mario's running animation, speed and movements in that game were influenced by Arale, the main protagonist of the 1980 Akira Toriyama manga/anime "Dr. Slump":


However, Dr. Slump's influence throughout the Mario series could trace back even further. Some particular examples from Mario games include:

• His running speed, animation, the Racoon and Tanooki Suits from Super Mario Bros. 3
• The Wing Cap from Super Mario 64
• The Cat Suit from Super Mario 3D World

Even traits of Mario's happy cartoonish personality, his short stature and gloves, and blue-red-overalls color scheme bear enough similarities that they all could have been taken from Arale's appearances and other elements throughout Dr. Slump. Despite this, outside of Miyamoto's comment, these connections are not known to have been elaborated on by any other employee from Nintendo.

A popular long-standing fan theory about Super Mario Bros. 3 was that it was actually an elaborate stage play.

The commonly cited evidence that supports this theory include:
•The game's title screen starts with the rise of curtains, and the game ends with the fall of curtains, as well as curtain calls for each World and several characters during the end credits
•Some platforms are hanging down from the "sky" by wires implying it's scenery being hung from the ceiling
•Some platforms are bolted to the wall and cast shadows against the "sky" suggesting it's a backdrop
•If Mario/Luigi kneels on white block platforms for six seconds, he will fall behind them and can walk behind the scenery
•Some platforms are sticking out through carved-out slots in the backdrop suggesting they are being controlled by hidden machines behind the set
•Each regular stage ends by exiting stage left and going "backstage" into the dark goal area
•Every injury or death in a stage is Mario/Luigi messing up the scene (the "Mario was never once in any real danger" part in the attached image is not necessarily true as unintended injuries and deaths can happen in theatre)

One overlooked piece of circumstantial evidence that supports this theory concerns the fact that the Kings of each World that are transformed into different creatures by the Koopalings are never actually seen being transformed into creatures, or transforming back into humans after Mario defeats a Koopaling. The way every Koopaling defeat plays out shows Mario falling from the airship holding the King's magic wand, the scene fades to black, and then the lights come back up inside the castle showing the King already transformed back into a human before either the wand or Mario return to the castle. This suggests that the Kings were never transformed in the first place, because they were all actors waiting to get into place for their scenes, and the transformations are the suspension of disbelief. It should be noted that the Game Boy Advance version of the game partially discredits this by adding cutscenes showing each King being turned into creatures by the Koopalings, but they are still are not seen being transformed back into humans.

In a Q&A interview to promote the release of Super Mario Maker in 2015, Shigeru Miyamoto confirmed the theory, that the game was all a performance.

Many international Mario fans were confused by the design of the Angry Sun in the New Super Mario Bros. U style of Super Mario Maker 2, noticing how it appeared more stern than angry. This is due to the fact that "angry" is not part of the enemy's name in Japan, just being called "sun", meaning that anger is not an inherent part of the character and giving it a different expression would make more sense without knowledge of its localized name.

The new design of the "Angry" Sun seems to be based on pre-colonial mythology based on the sun, most particularly the Inca sun god Inti, a design inspiration that seems to exist in anthropomoprhic suns from multiple other Nintendo games such as The Legend of Zelda: Ocarina of Time, Mole Mania, and Kid Icarus: Of Myths and Monsters