Sulawesi is an archaeologically important region in the Wallacea zone of Island Southeast Asia, as it lies on one of the proposed migration routes for human dispersals into New Guinea and Australia. Such a route would have required water crossings, as the island has always remained geographically isolated, yet ancient artefacts show that at least two hominin species reached Sulawesi during the Pleistocene era. By the Late Pleistocene, humans were painting what is now some of the oldest securely-dated parietal rock art in the world, in the limestone karst region of Maros and Pangkep in South Sulawesi. This region offers an excellent opportunity for investigating the prehistory of the island, as many of the numerous cave sites found here hold rich archaeological assemblages. However, phases of depositional deflation and erosion mean that interpreting the deposits is rarely straightforward. The majority of these cave sites are dominated by distinctive Mid-Holocene assemblages from what has been dubbed the ‘Toalean’ era. The Toalean range appears to have been constricted to southern South Sulawesi, but the origins of this this technoculture are ambiguous due to stratigraphic disturbances. Stone artefacts serve as a means for investigating the links between these significant periods of South Sulawesi’s prehistory as lithics are, as philosopher Henry David Thoreau poetically put in his journal “fossil thoughts… forever reminding me of the mind that shaped them”. Throughout the history of archaeology, researchers have attempted to use lithic artefacts as cultural markers, linking technological changes to the evolution of the human mind, as reflections of environmental pressures, as markers of community boundaries, or as indicators for the levels of regional contact. While stone artefacts are constrained by immediate conditions, including resource pressures, functional demands, and the cognitive capabilities of the various hominin species that produced them, within these restraints there is also room for diversity and at an assemblage-level this is shaped by culture. This thesis follows an approach built on the works of Moore, Tostevin, Davidson, and others, and reconstructs the processes of flake-removals while attempting to avoid laden assumptions about intent and function. In this thesis I explore the early lithic technologies of southern South Sulawesi as a proxy for cultural transmission through contact or ancestry. This thesis discusses the previous work that has been done in the region to date, and reports on three new excavations – a chert quarry site and two Toalean cave sites. Using data gathered from the lithic assemblage at one of these cave excavations, Leang Pajae, as well as observations gathered from across the region, I investigate and describe the Toalean technology in-depth. I also apply the same approach to the large lithic assemblage of the late Pleistocene cave site of Leang Bulu Bettue and the earliest hominin site of Talepu, collaborating with experts in the field to provide the first detailed systematic description of South Sulawesi’s Pleistocene technologies. This is presented as a thesis-by-publication through five publications, four of which have been published and one of which is ready to submit, as well as six surrounding chapters that provide the background, methodology, excavation context, and the unpublished comparison of the Late Pleistocene and Mid-Holocene stone artefact technologies. This thesis builds a description of the technologies that spans nearly 200,000 years. Using integrated quantitative and qualitative approaches, this thesis also assesses the technological changes that occur, from the earliest artefacts in South Sulawesi – made by an unknown pre-modern hominin species – to the artefacts of the Late Pleistocene Homo sapiens period that are associated with the production of portable art, ornamentation, and cave paintings, and finally into the ubiquitous yet enigmatic Mid-Holocene Toalean assemblages. In this thesis I show that the first technological shift was quite dramatic, with the oldest artefacts in Sulawesi being relatively large pieces that were produced on-site through low-effort reduction, and made on immediately available materials. In contrast, the early modern human assemblages are more complex, and imported materials were used to make statistically smaller and more diverse artefacts, some of which require multiple steps and pre-planning to produce. Deeper-layer artefacts recovered from both Leang Bulu Bettue and the neighbouring Pleistocene site of Leang Burung 2 reflect the same low-effort reduction of local materials observed at the Mid-Pleistocene Talepu assemblage; however the context of these ‘Lower Industry’ cave assemblages is still somewhat ambiguous. The transition to the Toalean phase is also distinct, but technologically less dramatic. It has been known for some time that the Toalean period is marked by the introduction of new lithic types in the form of stone and bone points and backed microliths. The research in this thesis has found that the change is more extensive than previously thought, as it also includes the addition of other new technologies not previously recognised, new reduction strategies, changing patterns in the distribution of flaking activities, but also the loss of certain complex reduction trajectories. A small amount of least-effort reduction of local materials – usually limestone – continued across all periods and into the Toalean, perhaps reflecting a convergence upon a convenient practice. This thesis concludes by discussing the implications of the technological changes and continuity. Large gaps in the archaeological record continue to pose a challenge to researching the transitional periods. However, from the data available, there is little reliable evidence for cultural contact between the first hominins and the early H. sapiens arrivals. There is much stronger evidence for continuity between the Late Pleistocene people and the Mid-Holocene Toaleans, and at this stage it is most parsimonious to suggest that the new Toalean stone artefact types and techniques are local innovations.