Cyan Guitars is a custom electric guitar workshop based in Hamburg, Germany, founded in 1989 by luthier Thomas Harm after he completed an apprenticeship as a carpenter. Harm first presented the brand at the Frankfurt Musikmesse in 1990, and the workshop has since operated from a series of Hamburg locations, settling in the Altona district on Stresemannstrasse. The shop emphasizes hand-built construction, with metal applications, pickup frames, and ornamental details fabricated in-house and CNC machinery reserved for fretboards, engravings, and serial metal parts.

The Cyan catalog is built around custom-order electric guitars, including T-style and S-style instruments, baritones, and 7-strings. Recurring model names include the Versatile, the Ultimate Rhythm Guitar, the Hellcaster, the Zodiac, and The Breed, alongside artist-driven signature builds. The workshop also offers repair, modification, and refinishing services.

The brand has long-standing ties to the German rock scene and has built instruments for Farin Urlaub of Die Ärzte, who has multiple Cyan signature models, as well as Chris Harms of Lord of the Lost. Cyan has also developed instruments in collaboration with members of Mastodon and with producer Jens Bogren, who worked with Harm on the Ultimate Rhythm Guitar concept.

Cyan Guitars has 2 products cataloged on Equipboard, including Solid Body Electric Guitars and Semi-Hollowbody Electric Guitars. Their gear is featured by 1 artist, with the strongest followings in Rock. Notable users include Farin Urlaub.