Land is a vital natural resource for the environment and socio-economic activities. Competing interests over land often lead to conflicts among actors with varying levels of power and influence, which are frequently linked to land-use changes. However, due to its complexity, the intricate relationship between land-use changes and associated conflicts remains underexplored. The Atlantic Forest of South America, a bio-culturally rich ecoregion, has experienced significant land-use changes over the last five centuries, including deforestation, agricultural expansion, urban development, and resulting land conflicts. Our study reviews, geolocates, and characterizes land conflicts in the Atlantic Forest from 1985 using a mixed-methods review and ordination of typologies of land conflicts. Results revealed disparities in indexed sources among Brazil, Argentina, and Paraguay, with Brazil dominating the production of sources. The identified land-conflict typologies reflected each country's socio-environmental history. In Brazil, agribusiness expansion displaced small producers and farmers; Argentina's forestry industry clashed with rural and indigenous communities; and Paraguay faced rapid deforestation and intensified land use driven by large landowners with the support of local authorities. These conflicts have caused severe social and environmental impacts, including land grabbing and forced land abandonment. This study is, to our knowledge, the first to spatially characterize land conflict typologies across a South American complex triple frontier. By providing interdisciplinary insights, it contributes to informing just territorial planning and a holistic understanding of land conflicts in the Atlantic Forest.