Transmutation refers to the act of transforming one substance into another. It was a goal of medieval alchemists, who wanted to turn lead into gold. Transmutation in fiction is usually accomplished in one of three ways:

- MagicMystical powers that can alter material
- Matter/Energy Manipulation: Re-arranging the molecular, atomic, or subatomic structure of a substance
- Reality WarpingSee the article on this term

Transmutation is often a very broken power, especially when it is capable of affecting living beings and not just inorganic material. It can be used to transmute enemies into harmless states, create weapons, destroy or disable enemy weapons, or even deconstruct enemies on a microscopic scale.

One particularly nasty use of transmutation is to turn half of the atoms in an opponent's body into antimatter (Composite Superman from DC did this once, but his victims were saved due to Pre-Crisis plot devices)

It is still possible to resist/negate, however, for example by beings that can control their own molecular structures.

Examples of characters that can transmute matter:

- Alchemists in Fullmetal Alchemist (matter manipulation, normally limited to inorganic matter)
- Many characters in DC Comics
- More than several Stands in Jojo's Bizarre Adventure (The methods are rather unclear, it depends on how you classify stands)
- Many characters in Marvel Comics
- Several Dragon Ball characters such as Akkuman, Boss Rabbit, Dabura, Majin Buu, Piccolo, and others
Yuki Nagato in The Melancholy of Haruhi Suzumiya
- Many characters in Tenchi Muyo!
- Several Warhammer 40,000 characters such as Magnus the Red, the God Emperor and the C'Tan
- Star Wars (Legends) characters (particularly Force Users like Naga Sadow, Exar Kun, Luke Skywalker, etc...)
- Former Crimson KingHishigi and several others in Samurai Deeper Kyo
- Strong magic users in My Little Pony - Friendship Is Magic
- Any god worth their salt in Hercules: The Legendary Journeys & Xena: Warrior Princess
- Many characters in the Greenverse

See also:

- Matter Manipulation