A home theater or home theatre is a theater built in a home, designed to mimic (or exceed) commercial theater performance and feeling, more commonly known as a home cinema. Today, home cinema implies a real "cinema experience" at a private home.

Today, a home cinema system typically uses a large projected image from a video projector or a large flat-screen high-resolution HDTV system, a movie or other video content on a DVD or high-resolution Blu-ray disc, which is played on a DVD player or Blu-ray player, with the audio augmented with a multi-channel power amplifier and anywhere from two speakers and a stereo power amp (for stereo sound) to a 5.1 channel amplifier and five or more surround sound speaker cabinets (with a surround sound system). Whether home cinema enthusiasts have a stereo set-up or a 5.1 channel surround system, they typically use at least one low-frequency subwoofer speaker cabinet to amplify low-frequency effects from movie soundtracks and reproduce the deep pitches from the musical soundtrack.