Plug-in

Plug-in, plug in or plugin may refer to:
 * Plug-in (computing) is a software component that adds a specific feature to an existing computer program.
 * Audio plug-in, adds audio signal processing features
 * Photoshop plugin, a piece of software that enhances the functionality of Adobe Photoshop
 * Plug-in electric vehicle, type of electric vehicle
 * Plug-in hybrid, a type of plug-in electric vehicle
 * Glade PlugIns, fragrance distribution product
 * Plug Ins, chain of electronics stores owned by Al-Futtaim Group

People with the surname

 * Vladimir Plugin (1937–2003), Russian historian and art historian