Skull Strings is a French manufacturer of guitar and bass strings aimed primarily at heavy metal and other extreme styles. The company is known for nickel-free stainless steel construction and for offering an unusually wide range of custom gauges, from .008 light tops up through .175 for extended-range bass. Alongside its standard sets, the catalog includes Drop D stainless, nickel-plated steel, Heavy Core, Exposed Core, and tapered-wound options, with custom handmade sets a core part of the brand's identity.

Production is based in France, where Skull Strings operates as a sub-brand of Tolito Musique. The strings are sold through the company's own shop as well as international retailers serving guitar and bass players who need non-standard gauges for low tunings, baritone scales, and 7-, 8-, and 9-string instruments.

Skull Strings has 6 products cataloged on Equipboard, including Strings. Their gear is featured by 1 artist, with the strongest followings in Rock and Metal. Notable users include Thomas Betrisey.