This article explores the sedimentology, stratigraphy, and paleo environments of Sidney Basin in Australia. It discusses the sequential geological history, sedimentary rocks, and principal sedimentary environments. The basin is filled with Permian shales and Triassic sandstones, and it has undergone uplift, folding, and faulting. The sedimentary environments include fluvial and shallow marine systems, coal measures, and embayment and shallow marine formations. Changes in sedimentary environments are influenced by erosion, climate change, and tectonism.