Thermionic Culture is a British manufacturer of all-valve (vacuum tube) professional studio outboard gear, founded in 1998 by veteran recording engineer Vic Keary and Jon Bailes. Based in Harlow, Essex, England, the company builds every piece of equipment by hand using traditional point-to-point wiring and quality audio transformers, with no transistors or integrated circuits in the signal path. Keary, who built his first recording studio in 1957 and spent four decades engineering at London studios including Lansdowne, Maximum Sound, and Chiswick Reach, channeled that experience into designing gear that showcases the sonic characteristics of thermionic valves.

The company's flagship product is the Culture Vulture, an all-valve stereo distortion and harmonic enhancer introduced alongside the company's founding, which has earned a devoted following among mix engineers and producers for its ability to add musical saturation and grit. Other key products include the Fat Bustard II twelve-channel valve summing mixer, the Phoenix line of valve compressors (spanning tracking, mix bus, and mastering variants), the Earlybird and Rooster mic preamps, and the Swift and Kite stereo equalisers.

Thermionic Culture gear is found in studios worldwide, used by producers and engineers such as Rik Simpson (Coldplay), Alan Moulder (My Bloody Valentine, Nine Inch Nails), Kurt Ballou, Gareth Jones, and Peter Katis. Universal Audio has licensed the Culture Vulture design as a UAD plugin, further extending the brand's reach beyond its hand-built hardware.

Thermionic Culture has 25 products cataloged on Equipboard, including Effects Processors, Preamps, and Mixers. Their gear is featured by 60 artists, with the strongest followings in Electronic, Rock, and Pop. Notable users include Liam Howlett, Lorn, and Tensnake. Most Thermionic Culture products sit firmly in the high-end, boutique range.