Railgun

could refer to:
 * Misaka Mikoto, the Level 5 esper of Academy City, nicknamed Railgun.
 * Railgun (ability), which is the official name of her Electromaster ability.
 * Railgun (special move), which is the signature move used by Misaka Mikoto.
 * Railgun, the first episode of Toaru Kagaku no Railgun S.
 * Toaru Kagaku no Railgun, manga/anime series involving aforementioned Level 5, also referred to as Railgun for short.