Fusion may refer to:
- The recurring ability.
- The act of fusing Materia from Crisis Core -Final Fantasy VII-.
- The term referring to fusing of planets from Final Fantasy IX.
- The skillchain from Final Fantasy XI.
- The act of fusing Magicite from Final Fantasy Crystal Chronicles.
- Prishe's skillchain attack from Dissidia 012 Final Fantasy.
- The type of spell from Vagrant Story.
Fusion, also called synthesis, is the process of combining two or more distinct entities into a new whole.