Thomas Organ Company was an American musical instrument and amplifier manufacturer based in Sepulveda, California, with additional operations near Chicago. Owned by Warwick Electronics Inc., the company is best remembered in the guitar world for its 1964 distribution deal with Jennings Musical Industries (JMI), which made Thomas Organ the exclusive U.S. distributor and, eventually, builder of Vox-branded amplifiers for the American market. Thomas Organ's U.S.-designed Vox line included solid-state amps such as the V-1 Pathfinder, V-2 Pacemaker, V-3 Cambridge Reverb, V-4 Essex Bass, and V-8 Berkeley Super Reverb.

The company's most culturally significant contribution was the invention of the wah-wah pedal. In late 1966, Thomas Organ engineer Brad Plunkett bread-boarded a pedal using a transistorized mid-range boost (MRB) circuit and the enclosure of a Vox Continental organ volume pedal. Released in 1967 under two names — the Vox Wah-Wah and the Cry Baby — the pedal became one of the defining guitar effects of the era and a staple across rock, funk, and psychedelic music.

Thomas Organ continued producing Cry Baby wahs in Sepulveda and later in Chicago into the late 1970s. When the company wound down its effects production in the early 1980s, Jim Dunlop acquired the Cry Baby rights and continued the lineage under Dunlop Manufacturing. Today Thomas Organ units from the 1960s and 1970s are collected as vintage effects, prized for their distinctive inductor-based voicing.

Thomas Organ Co. has 3 products cataloged on Equipboard, including Wah Pedals and Multi Effects Pedals. Their gear is featured by 17 artists, with the strongest followings in Rock, Blues, and Funk / Soul. Notable users include David Gilmour, Jimmy Page, and Jimi Hendrix.