The Chain Chomp is a video game character from Nintendo's Mario series of games. It is a black, spherical being, dog-like in personality, usually tethered to a block by a chain. It has sharp teeth and is constantly gnawing at the air and straining its chain, as if eager to "chomp" on any passers-by. Under unusual circumstances, it can come loose — for example, in Super Mario Bros. 3, when the in-game timer for the level hits 160 seconds.

Chain Chomps debuted in Super Mario Bros. 3 for the NES/Famicom, along with their cousins, the bounding Fire Chomps. Chain Chomps make their first appearance in level 2-5. They have since appeared in many Mario games, and made a cameo in the Legend of Zelda: Link's Awakening, as two pets in Mabe village, and in The Legend of Zelda: A Link to the Past as monsters that the player had to avoid. They also appear in level 5-4 of Yoshi's Island for the SNES. In Super Mario 64, they acquired their distinctive bark, which was also used in all further games it appeared in, save Paper Mario, where it was unleashed by Tutankoopa and made no distinctive sound, much like many of the other characters in the game. Also, in Mario Kart: Double Dash, the Chain Chomp is a useable item exclusivley to Baby Mario and Baby Luigi, pulling them forward for a few seconds without the use of the acceleration, and bowling over any other racers. In Paper Mario: The Thousand-Year Door, there are 2 kinds. Red Chomps, which appear in Glitzville, and original Chain Chomps, appearing in the Palace of Shadow.

Normally, they are invincible, but in some games are beneficial to the player as a form of propulsion. The Chain Chomp was used as a weapon by Bowser in SNES Super Mario RPG.