Thunder may refer to:
- The recurring element.
- The recurring spell.
- The recurring spellblade.
- The Lightning ability.
- The summon attack used by Ramuh.
- The summon attack used by Syldra.
- The Materia from Crisis Core -Final Fantasy VII-.
- The item from Final Fantasy Adventure.
- The enemy from The Final Fantasy Legend.
- The enemy and the support ability from Final Fantasy Legend II.
Thunder is the sound caused by lightning. Depending on the distance and nature of the lightning, thunder can range from a sharp, loud crack to a long, low rumble (brontide).