Soil fungi are among the most diverse and dominant organisms on planet Earth. They play essential roles in key ecosystem functions, and influence diversity and distribution of plants and animals via symbioses and pathogenicity. Yet, unlike their above-ground counterparts, we know little about the identity, distribution and ecological drivers of dominant soil fungi worldwide. In this work, we surveyed 235 sites collected across 18 countries, covering nine biomes (temperate, tropical and dry forests, cold, temperate, tropical and arid grasslands, shrubland, boreal) of the globe to investigate identity, occurrence and ecology of dominant fungal phylotypes in soil. We used a suite of statistical approaches to characterise the distribution and habitat preferences of dominant fungi in relation to edaphic and climatic variables, and mapped their expected geographical distribution and abundance. Additionally, we used whole-genome comparisons to assess the importance of functional attributes in explaining the observed patterns of fungal dominance. Our results provide novel evidence that less than one hundred (< 1% of the retrieved fungi) fungal taxa from a single phylum, Ascomycota, are dominant in soils across the globe, and display a range of environmental preferences, mainly ascribed to differences in climatic conditions. These dominant fungal taxa are characterised by remarkable dispersal abilities, generalist life- styles, and increased genomic potential for resource utilisation, competition and stress tolerance. Our findings suggest that these traits, combined, help explain the success of abundant and ubiquitous fungi in colonising a vast array of ecosystems. This study represents a step-change advancement in our understanding of the patterns and mechanisms driving dominant soil fungal communities in natural ecosystems worldwide. By building a novel, fundamental understanding of distribution, ecological attributes, and patterns of dominance of soil fungi on a global scale, this work opens new leads to develop approaches and strategies aiming at preserving soil fungal diversity and ecosystem functions fungi carry out.