Abstract Multi-omics analyses have significantly advanced the understanding of complex marine microbial communities and their interactions. Despite notable progress from recent large-scale ocean meta-analysis efforts, the effective integration and accessibility of these diverse datasets remain challenging. To address this, we introduce Ocean-M (http://om.qnlm.ac), a comprehensive and publicly accessible platform for marine microbial multi-omics data integration, analysis, and visualization. Ocean-M provides a systematic view of 54 083 high-quality metagenome-assembled genomes, including genome assembly statistics, genome clustering, gene annotation, and interactive tools for global-scale taxonomic profiling. The platform also incorporates microbial community networks, host–microbiome interactions, and environmental DNA datasets to support an integrated ecological framework for studying microbial interactions and ecosystem functions. Additionally, Ocean-M enables large-scale mining of ecologically and biotechnologically important genes, with curated catalogs of 151 798 biosynthetic gene clusters, 52 699 antibiotic resistance genes, and millions of carbohydrate-active enzymes and plastic-active enzymes. By combining multi-omics data with environmental metadata, Ocean-M serves as a valuable resource for advancing marine microbial ecology, global biogeography, and functional gene discovery.