13 sedimentary rock samples from Proterozoic through to Mesozoic formations intersected in 5 Officer Basin wells yielded apatite fission track analysis data (track length and density) used to interpret, via statistical modelling, the broad geothermal history of the region. The technique enables estimation of the maximum palaeotemperatures reached by the sediments via their apatite fission track annealing history since grain deposition, which in turn allows estimation of maximum depths of burial, while the sediments' apparent fission track age compared with their stratigraphic age gives insights into subsequent cooling regimes and the time span of tectonic events (unconformities) of otherwise uncertain duration. The study conclusions were as follows: - All Proterozoic and Cambrian samples show evidence of cooling from temperatures greater than or equal to 100 degrees Celsius during the Alice Springs Orogeny (395 - 290 Ma). Unfortunately, the AFTA data does not constrain palaeotemperatures from earlier events; - All 13 samples appear then to have been reheated to 90-100 degrees C prior to a second, pre-Mesozoic cooling event occurring between 110 and 70 Ma; - Most samples also show evidence of a third cooling event from temperatures of 60-70 degrees C during the last 50 Ma; - The elevated temperatures associated with the last two events are probably related to increased depth of burial, but may also be caused by the sampled rocks once acting as aquifers carrying heated water; - The Proterozoic and Cambrian samples analysed were probably well within and possibly passed through the oil window prior to cooling during the Alice Springs Orogeny, whereas the Permian and Mesozoic samples tested appear only to have entered the upper part of the oil window prior to their stepped cooling phases extending from 110 Ma and 70 Ma respectively.