McGrath Guitars is a small, family-run custom bass shop based in San Diego, California. Founded by bassist and builder Cormac McGrath, the company focuses on handcrafted electric basses designed around playability and ergonomics rather than display-case aesthetics. The shop's signature look comes from Cormac's wife Madelyn McGrath, a graphic designer and artist who hand-stains each instrument.

The lineup centers on the Thunderhorse IV and Thunderhorse V models, offered both as in-stock instruments and through an online Bass Builder that lets customers configure woods, pickups, and finishes. Alongside the main bass range, the shop sells a smaller selection of guitars and branded merchandise.

McGrath operates as a two-person workshop, building and finishing basses in-house with a stated emphasis on instruments that feel effortless to play. Direct sales run through the brand's own site and its Reverb storefront.

Mc Grath Guitars has 1 product cataloged on Equipboard, including Electric Basses.