An AV receiver, or audio/video receiver, is a consumer electronics component used in a home theater system. Its primary function is to receive audio and video signals from multiple sources, process them, and provide power amplifiers to drive loudspeakers and route the signals to their respective outputs. AV receivers are used to distinguish multi-channel audio/video receivers from simpler stereo receivers, although the primary function of both is amplification. AV receivers may also be known as digital audio-video receivers or digital media renderers.

AV receivers have several features that distinguish them from stereo receivers. For example, stereo receivers have two channels of amplification, while AV receivers may have more than two. The standard for AV receivers is five channels of amplification, usually referred to as 5.1 receivers, which provide for a left, right, center, left surround sound, and right surround sound speaker to be powered by the receiver. AV receivers also have a variety of possible connections, including analog audio, digital audio, composite video, S-Video, and SCART video.

AV receivers are classified as an audio frequency electronic amplifier, but with the addition of several features in the 2000s, AV receivers in the 2010s generally have significant additional functionality. For example, they may support several movie soundtrack formats such as Dolby Digital, Atmos, and DTS, and have built-in audio effects to enhance music and movies. AV receivers are also far more likely to offer features like room correction, Bluetooth, wireless functionality, and more.

AV receivers are notoriously complex, with reams of features and confusing technical specifications. However, they are the hub of a home theater system and assist in connecting, setting up, and optimizing home theater systems via a simple user interface. They also offer a range of other features, such as internet connectivity via Ethernet ports or WiFi, wireless music streaming via Bluetooth, wireless video casting or screen mirroring via DLNA/Miracast/Airplay, multi-room audio output, and even DSP-based room-calibration for optimized sound.

In summary, an AV receiver is an audio/video receiver used in a home theater system to receive audio and video signals from multiple sources, process them, and provide power amplifiers to drive loudspeakers and route the signals to their respective outputs. They are more complex than stereo receivers and offer a range of features, including support for movie soundtrack formats, room correction, Bluetooth, wireless functionality, and more.