Human metapneumovirus (hMPV) is a significant respiratory pathogen affecting populations worldwide, particularly young children, the elderly, and immunocompromised individuals. Despite its clinical importance, the intrinsic disorder status of hMPV proteins and their roles in the pathogenic mechanism remain largely unexplored. Intrinsically disordered proteins (IDPs) and disordered protein regions (IDPRs) are members of the "dark proteome," characterized by the absence of a stable three-dimensional structure but with critical biological functions, such as host–virus interactions and immune evasion. In this study, we evaluated the prevalence and functionality of IDPs/IDPRs in the hMPV proteome using computational tools, including PONDR®, IUPred2A, DISOPRED, and ESpritz, validated with NMR, X-ray crystallography, and DisProt data. Our findings revealed significant levels of intrinsic disorder in key hMPV proteins, such as the fusion (F), nucleocapsid (N), and glycoprotein (G), which are implicated in viral replication, host entry, and immune modulation. Proteins SPQ8B9Q8 and SPQ6WB94 showed 100% intrinsic disorder, highlighting their potential roles in immune evasion, while structural proteins like SPQ6WB99 displayed minimal disorder. The hMPV proteome exhibited a mean disorder percentage of 19.19%, with nearly half of the proteins containing disordered regions exceeding 30 amino acids. These findings emphasize the critical role of intrinsic disorder in the hMPV life cycle and identify IDPs/IDPRs as promising targets for disorder-based drug design.