Tiny-Huge Island is an island surrounded by cliffs and an ocean in Super Mario 64 and Super Mario 64 DS. It is the thirteenth course in the game and is located on the second floor of the castle. This level has many coins, with 191 total, many of which come from Ground Pounding on the big Goombas for one blue coin each.
Strategically placed around the island are Warp Pipes that can alter the size on the entire level, a feature reminiscent of Super Mario Bros. 3's Level 6 of Big Island, where there are doors that change the enemies' sizes. The main creatures in the level are Piranha Plants that shoot fire, Koopas, Lakitus, Koopa the Quick, Bubbas, and Goombas. All can change in size and be replaced. When in the huge version of the island, two Bubbas are in the water, Goombas and Piranha Plants are huge, Koopa the Quick is present, and a cannon is available. The boss of this level is a Wiggler.
A unique feature of this level is the option to choose how the level first appears. It is also unique in that it can be entered via two paintings, one small and one large, located to the left and right, respectively, of a central painting, which Mario cannot enter. The entrance room employs forced perspective, which gives the illusion that all three paintings are the same size. Entering the small painting causes the island to begin "tiny" (Mario thus beginning significantly larger than everything else in the level). Entering the large painting causes the island to begin "huge" (Mario thus being extremely small compared to other objects and enemies throughout the level).
The course itself may be a reference to island gigantism, a phenomenon where in the species of the inhabitants of a distant island are much larger than they are on more familiar, industrialized land.
 Star 1: Pluck the Piranha Flower
To get this Star, Mario must enter the small painting, arriving in the "tiny" island. There are two islands in line with the island where Mario sets out his adventure in the level. Mario must Long Jump or swim to the first island then jump/swim again to the next island. Mario must then jump through the pipe, to make the island huge. In the spot, there will be lots of Big Venus Fire Traps on the island now. Mario must dispose of them all, most easily by punching them, or walking on them with the Super Mushroom to get the Power Star. This doesn't work on the "huge" side because the islands are too far away to Long Jump to and too tall to reach by swimming.
 Star 2: The Tip Top of the Huge Island
For the next star, Mario must again enter the small painting. Then he should get up to the third island, but this time, Mario must go to a small platform just next to the small island and press the switch that is on it, revealing a bridge which Mario must walk over to where the bridge turns, then get off onto a platform. He must jump up to the next platform, avoiding the Big Steelies before jumping through the pipe, making him small. Mario should then make it up to the top of the Island from there, where he will find a ! block which contains the star.
 Star 3: Rematch with Koopa the Quick
For this star, Mario must once again enter the small painting and get to the third island. Next, he should pass through the Windswept Valley bridge. Up on the next platform, Mario will find Koopa the Quick (unless he is on the tiny version of the island, where there is a smaller Koopa that cannot be raced but can be squashed for a Blue Coin). Mario must then race him to Windswept Valley where a flag is seen. If Mario wins, he will be awarded the star.
 Star 4 (64): Five Itty Bitty Secrets
For this Star, Mario must again be on the small island. The mission involves finding five openings all around the tiny version of the island. The openings are found at the following locations.
After all five holes have been found, the Star appears on a small floating island near the start. To access it, the player must hit the ! Switch behind the pipe near the entrance to the course, and must follow the bridge it creates to the island.
Note: Secrets can be found in any order.
 Star 4 (DS): Klepto the Condor
This star appears in the DS version only. For this star, Mario will have to enter either painting and go to where the Power Star would go In "Five Itty Bitty Secrets" Where he will find Klepto the condor from Shifting Sand Land, and his pattern is the same as In The Talons Of The Big Bird. Just hit Klepto to collect the Power Star.
 Star 5: Wiggler's Red Coins
This time, Mario must go through the large painting. He must go through the opening at the start and swim across the lake, going into the cannon to shoot himself on the platform with the tree and wooden bridge connected to it. Mario must then walk on this narrow bridge. At the end of the bridge, there is an opening into a cave. When Mario is inside, he must jump on the various platforms and collect the eight Red Coins. The star will then appear on the star marker at the entrance to the cave.
 Star 6: Make Wiggler Squirm
For this star, Mario must go through the small painting. He must get to the top of the island, where he will find a pool. Mario must ground pound the pool, making the water flood through a small opening. Mario must then make his way back the way he came until he gets to a pipe. He must then jump through the pipe into Huge Island and then get back to the top of the island again and jump through the opening. Mario will find himself in Wiggler's Cave, where a Wiggler will say that it is really angry because Mario flooded its house. Mario must then Stomp it three times on the head to make it give up the star. If one is to look through the grate in the floor using the first person camera-mode, a miniature of the Wiggler can be seen. The player can also see this small Wiggler in "Wiggler's 8 Red Coins" if one returns to that level after defeating Wiggler. This does not happen in the DS remake.
In the DS version of the game, Wiggler turns red after taking damage twice (as shown in the screenshot).
 Star 7 (DS): Switch Star on the Island
In Wiggler's Cave, the player must hit the Star Switch and find a way over to the Star before it disappears. Mario or Luigi is best suited for getting this Star. The best route is either a jump to the next ledge followed by a long jump (this is best suited for Mario) or instead of a long jump, a backflip (Luigi only).
 Names in Other Languages
|SpaEM=Great Small Island
|GerM=Pun on the novel Gulliver's Travels and the German name for "Goomba"
|Ita=Mini-Grande Isola (64)