Kjaerhus Audio is a Danish developer of VST audio plugins founded by Torben Larsen, known for emulating the warmth and saturation of vintage analog studio gear from the 1970s and 1980s. The company built a reputation primarily through its free Classic Series, a bundle of mixing and mastering plugins that includes the Classic Compressor, Classic EQ, Classic Reverb, Classic Delay, Classic Chorus, Classic Flanger, Classic Phaser, Classic Auto-Filter, and Classic Master Limiter. The Classic Series became a staple in home studios and DAW templates due to its low CPU usage and analog-flavored sound on a free price tag.

A paid commercial line, the Golden Series, expanded on the Classic plugins with more advanced signal paths and a gold-themed interface. Notable Golden Series titles include the Golden Audio Channel (GAC-1) strip with built-in EQ, compression, gating and de-essing, the Golden Equaliser (GEQ-7), the Golden Compressor (GCO-1) with multiple compressor models such as Classic, Opto, Smooth and Pumping, the Golden Modulator (GMO-1) for chorus, flange, tremolo and vibrato, the Golden Audio Gate (GAG-1), and the Golden Peak-Pressor (GPP-1). The plugins are 32-bit Windows VSTs and are often cited on production forums for their character on drums, vocals and bus processing.

Kjaerhus Audio has 10 products cataloged on Equipboard, including Limiter Plugins, Reverb Plugins, and Compressor Plugins. Their gear is featured by 15 artists, with the strongest followings in Electronic, Pop, and Rock. Notable users include Insan3lik3, Glenn Fricker, and Laidback Luke.