Oldhamia is an ichnogenus describing burrows produced by worm-like organisms mining underneath microbial mats. It was common from the Early Cambrian deep-water deposits. The Ediacaran species Oldhamia recta are body fossils of a rod-like organism, rather than ichnofossils. The Ordovician Oldhamia pinnata and Carboniferous-Permian Oldhamia fimbriata were mentioned without any ichnotaxonomical formalization, and therefore are nomina nuda. It was named after the geologist Thomas Oldham.