Activator

Activator may mean:
 * Activator (genetics), a DNA-binding protein that regulates one or more genes by increasing the rate of transcription
 * Activator (proteomics), a type of effector that increases the rate of enzyme mediated reactions
 * Sega Activator, a motion-sensing controller for the Sega Genesis
 * Activator technique, a method of spinal adjustment
 * Activator, a hardcore band from Brooklyn Ny.