Mellowmuse is a London-based pro-audio plugin developer founded by Gary Newby in 2008. Operating as a small, focused outfit, the company produces VST, VST3, AU, and AAX plugins for Mac and Windows aimed at musicians, producers, and engineers working in the box.

The catalog centers on mixing and mastering tools with an emphasis on classic analog character. Notable releases include the ATA Auto Time Adjuster, the CP1A compressor, the CP2V and CP3V vintage compressors, the CS1V console channel, the EQ1A channel equalizer, the EQ2V vintage equalizer, the EQ3V mastering equalizer, the IR1A convolver, the LM1V mastering limiter, and the SATV vintage saturator. The plugins are distributed directly and through retailers such as Plugin Boutique and PluginFox.

Mellowmuse has 11 products cataloged on Equipboard, including Compressor Plugins, Reverb Plugins, and EQ Plugins. Their gear is featured by 1 artist, with the strongest followings in Electronic. Notable users include Mr. Bill.