Phantom fx is a Japanese boutique effects pedal brand founded in 2007 by guitarist Masafumi Todaka (also known as Toddy), who plays in bands such as ART-SCHOOL and MONOEYES. The brand emerged during Japan's second boutique effects boom and built a cult following despite a small catalog, with each release tending to sell out quickly among Japanese pedal enthusiasts.

The brand's early run from 2007 to 2013 produced a handful of much-discussed pedals including the Sabbath fuzz, the Fluid overdrive/distortion, the Ruins, and the Bells, an overdrive collaboration with designer Shun Nokina (Leqtique) loosely inspired by the BJFE Honey Bee. After several years of dormancy, Phantom fx returned in 2020 with the MOTHER, a Big Muff-style fuzz built around hand-selected NOS and vintage transistors, with Egawa of Sara Pedals joining as production lead.

New Phantom fx releases are sold primarily through the Tokyo-based retailer CULT Pedals, which has carried later models such as MOTHER, MOTHER+, and Sabbath "Black Gaze." The pedals are typically built in small batches and aimed at players looking for fuzz and dirt voicings rooted in classic circuits but tailored for live use.

Phantom FX has 3 products cataloged on Equipboard, including Fuzz Effects Pedals and Overdrive Effects Pedals. Their gear is featured by 3 artists, with the strongest followings in Rock and Pop. Notable users include Yusuke (Lynch), Kengo Matsumoto, and Masafumi Todaka.