Monson Guitars is a custom electric guitar and bass workshop founded by Brent Monson in January 2001. Originally based in Northern California near Chico, the operation later relocated to the Seattle, Washington area, where Brent hand-builds, signs, numbers, and dates each instrument one at a time rather than running a production line.

The shop is best known within extreme metal and underground guitar circles for offbeat, often aggressively shaped originals with names like the Impaler, Nomad, Defiance, Redemption, Sorcery, Abyss, Berserker, and the Atrocity, alongside basses such as the Plague, Hrym, and Antithesis. Monson positions its instruments as extreme yet affordable for working underground musicians, leaning toward unconventional body shapes, exotic woods, and one-off custom configurations rather than catalog uniformity.

The brand has built a reputation through endorsements in the black, doom, and extreme metal scenes, with players from Enslaved, Wolves in the Throne Room, Leviathan, Hulder, Helheim, Indian, and U.S. Christmas among those associated with the shop. Monson was also an official sponsor of the 2018 Decibel Magazine Tour.

Monson has 6 products cataloged on Equipboard, including Solid Body Electric Guitars and Electric Basses. Their gear is featured by 6 artists, with the strongest followings in Rock, Metal, and Electronic. Notable users include "Wrest" Jef Stuart Whitehead, Grutle Kjellson, and Mike Scheidt.