Soil biodiversity is important to support ecosystem services and productivity of agriculture through the mediation of nutrient cycling, soil structure, decomposition of organic matter, and plant health. But climate change is now posing a major threat to soil biodiversity globally. This chapter considers how increases in temperature, changes to precipitation regimes and greater occurrence of extreme weather events are transforming soil biological communities and impacting their ecological functions. Soil harbours more than 25% of global biodiversity, but a high level of this diversity is still underexplored. It is believed that describing soil microbial species will make up only 1% of the diversity, indicating a substantial unknown of the belowground ecosystems. Many of the most important soil organisms bacteria, fungi, protozoa, nematodes, arthropods, and annelidsare quite sensitive to changes we are making in the environment. Temperature and moisture regimes changes of living activity, reproduction rates and spatial distribution, with consequent impacts on soil processes. For instance, drought can decrease microbial biomass by c. 50% whereas a long-term warming treatment might promote organic matter mineralization and CO₂ and N₂O emissions in soil. The chapter provides evidence that soil fauna and microorganisms are stressed in response to changing climates, which causes changes in food web structure and functional diversity losses. In addition, changes in vegetation, litter input and root exudation patterns, caused by climate, also affect the composition of the microbial communities. In agricultural contexts, the effects are magnified by injurious practices including monoculture, high chemical use, and intensive cultivation that lead to deteriorating biodiversity and reduction of soil defence powers. In light of this, the present chapter highlights the significance of adaptive and sustainable soil management to maintain soil biodiversity in a climate-change perspective. Conservation tillage, organic amendment, crop rotation, cover cropping, and agroforestry are some of the methods that can be used to combat degradation and biodiversity loss. The chapter also highlights that the improvement of the monitoring of soil biodiversity, the inclusion of soil biological indicators in climate models and a higher policy attention to soil live for ecology and climate resilience are necessary.