El Rey Effects is a boutique guitar pedal company based in Cincinnati, Ohio, founded by Jimmy Nielsen. The pedals are hand-wired using high-quality components and backed by a lifetime warranty on internal parts. Nielsen, a musician and engineer by trade, started the company after building a homemade boost pedal that friends kept requesting. El Rey Effects operates as a small team of family and friends, with a mission to deliver quality effects at accessible price points for working musicians.

The company is known for its distinctive, eye-catching pedal designs that draw on eclectic visual themes. The Lucha Fuzz is an op-amp style fuzz with Mexican wrestling-inspired graphics and controls labeled "Headlock," "Grapple," and "Pile Driver." The Mystic is a Burr Brown op-amp-based fuzz with an Ouija board motif and an adjustable clipping switch. The Fuzz de la Muerte is a silicon fuzz with an on-board gate and three-way color selector switch, which received a Guitar Player Magazine Editor's Pick Award. The Chicago Typewriter is a tremolo pedal — named after 1930s slang for a machine gun — featuring a volume boost capability that sets it apart from typical tremolo designs. El Rey Effects also offers custom hand-painted graphics on request.

El Rey Effects has 2 products cataloged on Equipboard, including Tremolo Effects Pedals and Fuzz Effects Pedals.