The Earth’s permanently cold biosphere is known to harbour abundant microbial biomass and represents a rich resource for the discovery of novel cold-adapted microorganisms, many of which form part of the ‘microbial dark matter’ which cannot be analysed using traditional culture-dependent approaches. The recent development of metagenomics and related multi-omics strategies has provided a means by which entire microbial communities can be studied directly, without the prerequisite of culturing. The advancement of the ‘omic’ methods is directly linked to recent progress in high-throughput sequencing, robust data processing capabilities and the application of cutting-edge analytical tools for high-throughput detection of biomolecules. The combined application of these tools and strategies has provided an unprecedented access to the structure and potential function of microbial communities in cold environments, providing increasingly comprehensive insights into the taxonomic richness and functional capacity of the indigenous microorganisms. Applications of ‘omic’ strategies have enhanced our understanding of psychrophilic adaptation mechanisms, revealing the versatility and adaptability of life in the ‘cryosphere’. In addition to the predicted roles of psychrophiles in biogeochemical cycling, recent multi-omic studies have further emphasised the importance of the ‘cryosphere’ in influencing global atmospheric conditions. Finally, metagenomic bioprospecting of cold environments has yielded a variety of novel bioactive molecules including novel ‘psychrozymes’, with a wide range of potential industrial and biotechnological applications. Here, we have provided an overview of recent developments in metagenomic technologies and their application in the study of the cold biosphere.