Stromatolites are broadly known to be microbially-mediated structures formed through biomineralization, photosynthesis, organic decay and sediment trapping and binding. These sedimentological structures exhibit laminated domes, branching columns, superposed cones, egg-carton topographies, and wavy laminations. These extraordinary objects have been used to argue for the past activity of oxygenic and/or anoxygenic phototrophs that inhabit the topmost layers of modern stromatolites, hence they have major implications for past global environmental change, such as the Great Oxidation Event. While some stromatolites date back at least to 3.71 billion years ago in the Isua Supracrustal Belt, younger examples preserve some of the most compelling signatures of life’s evolution during the Precambrian. However, stromatolites can also be formed by abiotic processes, such as in chemically oscillating reactions, as well as in the absence of visible light, such as in deep-sea hydrothermal vents and ferromanganese nodules. Considering these alternative formation models, and the potential planetary biology analogue that stromatolites could represent in outcrops on other planetary surfaces, the time is now ripe to create a systematic survey of all possible biosignatures in stromatolites from the Precambrian record to generate a synthesis of all possible biosignatures in stromatolites. This work will capitalise on the extensive datasets published in the peer-reviewed literature as well as benefit from Prof Papineau’s extensive collection of Precambrian stromatolites. The outcome of the research will be directly applicable to the search for evidence of past life on Mars.