<p>Pasture systems strongly influence microbiome diversity in both soils and grazing ruminants, and their interactions through interconnected microbial exchange pathways. In temperate regions, grazed pasture systems are predominantly composed of perennial ryegrass-white clover, representing standard systems under contemporary management. However, sustainable alternatives such as regenerative agriculture, which emphasise diverse pasture species, are gaining attention. Diverse pastures, due to their varied root structures and nutritional composition, exert more pronounced effects on soil and ruminant microbiomes than standard swards. This review synthesises current knowledge on soil and ruminant gut microbiome responses to diverse pasture systems. Diverse swards enhance soil organic carbon and microbial abundance, while their varied nutrient profiles and bioactive compounds, together with ingested soil microbes during grazing, contribute to a more diverse and stable gut microbiome, potentially strengthening soil–gut microbial interactions. However, few omics-based studies have explored microbiome responses to pasture management, and none have simultaneously investigated soil and ruminant gut microbiomes under regenerative management. This review highlights these gaps and proposes future research directions, including integrated multi-omics approaches, to advance understanding of soil–gut microbiome dynamics, interactions, and functional roles within pasture-based agroecosystems.</p>