AC97 (Audio Codec 97) is a standard audio interface used in PCs and laptops for connecting audio devices such as sound cards, speakers, and microphones. Intel developed it in 1997, and it became a widely adopted standard for integrating audio into motherboards.

The AC97 interface uses a codec (coder-decoder) chip that converts digital audio signals into analogue signals that can be outputted to speakers or headphones and vice versa. It supports stereo and multi-channel audio with a maximum sample rate of 96 kHz and up to 20-bit resolution. AC97 also supports software-based audio processing, such as equalization and 3D sound effects. In recent years, AC97 has been replaced by newer audio standards, such as HD Audio, which offer improved audio quality and functionality.