Black Market Custom (BMC) is a Massachusetts-based builder of hand-made guitar and bass speaker cabinets, along with custom drum kits. The company was founded by Chris Constantino in January 2009, initially focused on drums before expanding into amplifier cabinets through a partnership with a builder who had been making custom cabs since 2006. BMC positions itself as a boutique shop run by working musicians, with the idea that the same people who design the gear also tour with it.

The cabinet line is built from voidless Baltic birch and offered in a range of configurations including 1x12, 2x12, and 4x12 models, with the V-Series 2x12 among their better-known designs. Speaker loadouts typically include Celestion Vintage 30s or Eminence drivers, and the company offers custom tolex, grille, and piping options so that a player's cabs, drums, and road cases can be visually coordinated. BMC drums are similarly built to order with buyer-specified shells, finishes, and hardware.

The brand has a following within heavier guitar-oriented scenes and has been associated with bands including The Chariot, A Faylene Sky, and Authors. Products are sold through their own shop as well as through dealers and secondary marketplaces such as Reverb and Guitar Center.

Black Market Custom has 6 products cataloged on Equipboard, including Guitar Amplifier Cabinets and Bass Amplifier Cabinets. Their gear is featured by 4 artists, with the strongest followings in Rock. Notable users include Justin Morrow, Aj Rebollo, and Alan Day.