Given the potential role of phages in modulating microbial population, metabolism, and evolution, virome has been recognized as an indispensable yet underexplored component in microbiomes. Our understanding of the rumen virome, however, is derived from a few culture-dependent studies. To address this knowledge gap, we mined 975 published rumen metagenomes for viral sequences and created the first rumen virome database (RVD) representing 397,180 species-level viral operational taxonomic units (vOTUs). Most of the vOTUs were not classified to any existing taxa. The classified vOTUs represent viral lineages distinct from those found in the human gut microbiome. Functionally diverse auxiliary metabolic genes and antibiotic resistance genes were carried by some rumen viruses and they may affect the physiology of their hosts and the rumen fermentation process. The RVD database and the major findings of the rumen virome analyses can help and inform future studies on rumen virome.