Pilbaria is a genus of fossil stromatolite-forming cyanobacteria from the Paleoproterozoic era 2.3 to 1.7 billion years ago.

[3][2] The type species, Pilbaria perplexa is characterised by long, mostly straight, subparallel and mostly smooth columns with proportionately small transversely elongate niches with projections.

[1] Fossils of P. perplexa, the type species, have been found in the Wyloo Group of the Pilbara region in Western Australia, aged 1.7 to 2 billion years old.

It has also been found in the Epworth Group of the Coronation and Pine Creek Geosynclines in Canada, aged 1.865 to 2.2 and 2 to 2.3 billion years old.

P. boetsapia and P. inzeriaformis are from Schmidtsdrift Formation of the Northern Cape Province in South Africa, aged approximately 2.2 billion years old.