The Tectonic Geology Data Set is a digital interpretation of the Tectonic Geology of the Province of Ontario, It illustrates this by 1) grouping volcanic and sedimentary rock units into tectonic assemblages in Precambrain terrains and depositional sequences in the overlying Paleozoic and Mesozoic sedimentary basins; and 2) interpreting the ranges of emplacement ages of all major intrusions and grouping some plutons into suites. Among a range of tectonically significant features, the map also displays major folds, faults, stratigraphic younging directions, interpreted centres of volcanism and locations of U/Pb age determinations, which are numbered and cross-referenced to a table of ages. This map represents the first attempt internationally to subdivide Archean rock units into Tectonic assemblages, and the first attempt in Ontario to subdivide Paleozic and Mesozoic rock units into depositional sequences. The purpose of this map is to portray the distribution of magmatism and sedimentation in time and space in the rock record of Ontario. The intended user is a geologist with an academic or applied mineral exploration interest in the components of the bedrock of Ontario that forms the basis of its geochronometric and tectonic record.