Archidesmus is an extinct millipede genus from the Lower Devonian Old Red Sandstone of the United Kingdom.

Individuals were up to 5 cm (2.0 in) long, and had 60 to 80 body segments decorated with tubercles (bumps) on the upper surface, and most segments possessed wing-like keels (paranota) extending to the side.

The type species Archidesmus macnicoli was described by British paleontologist Benjamin Peach in 1882.

[1] A second species, A. loganensis was also described by Peach[2] but its status as a valid species- or even a myriapod- is debated.

This prehistoric myriapod-related article is a stub.