Reactor may relate to the following:

• A chemical reactor: a device for containing and controlling a chemical reaction.
• A nuclear reactor: a device for containing and controlling a nuclear reaction.
• An inductor (possessing reactance) in an electrical power grid.
• An arcade game entitled Reactor, also released for the Atari 2600 console.
• A rock band, named Reactor.
• Reactor (Havok): A production from Havok software .
• Re-ac-tor, a 1981 album by Neil Young and Crazy Horse
• A broadcast station in Mexico City, "Reactor (radio station)"

Reaktor | Reaktor | Reactor | Reaktor | Реактор | Reaktori