Lightspeed may refer to:
- The battle element from Lightning Returns: Final Fantasy XIII.
- The ability from Final Fantasy XIV.
- The enemy ability from Final Fantasy Tactics Advance.
- The enemy ability from Final Fantasy Record Keeper.
speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its value is exactly 299792458 metres per second (≈3.00×108 m/s), as the length of the metre is defined from this constant and the international standard for time. According to special relativity, c is the maximum speed at which all matter and information in the universe can travel.The