Human histone H1 subtypes interaction networks was constructed to show a spectrum of their activities realized through the protein-protein interactions. Histone H1 subtypes participate in over half a thousand interactions with nuclear and cytosolic proteins engaged in the enzymatic activity and binding of nucleic acids and proteins. Small scale networks created by H1 subtypes are similar in their topological parameters (p > 0.05) but hub proteins of the networks formed with subtype H1.1 and H1.4 differ from those of subtype H1.3 and H1.5 in the closeness centrality, clustering coefficient and neighborhood connectivity (p < 0.05). Molecular function and biological process of the networks hubs is related to RNA binding and ribosome biogenesis (subtype H1.1 and H1.4), cell cycle and cell division (subtype H1.3 and H1.5) and protein ubiquitination and degradation (subtype H1.2). Such a disparity between H1 subtypes is also manifested by enriched GO terms of their interacting proteins. The residue propensity and secondary structures of interacting surfaces as well as a value of equilibrium dissociation constant indicate that a type of H1 subtypes interactions is transient in term of the stability and medium-strong in relation to the strength of binding. Histone H1 subtypes bind interacting partners in the intrinsic disorder–dependent mode, according to the coupled folding and binding and mutual synergistic folding mechanism. These results evidence that multifunctional H1 subtypes operate via protein interactions in the networks of crucial cellular processes and, therefore, confirm a new histone H1 paradigm relating to its functioning in the protein-protein interaction networks.