Margarinotus brunneus is a species of beetles belonging to the family Histeridae.

[2] Margarinotus brunneus can reach a length of about 5.5–8.5 millimetres (0.22–0.33 in).

Body is shiny black in colour.

These beetles are characterized by the presence on the pronotum of complete marginal stria, by two lateral pronotal striae and basal fragments of the 5th dorsal striae.

[4] It has been introduced into eastern North America.