Advances in the field of hydrogel research have unlocked multiple exceptional features like porosities, interfacial interactions, dynamics, mechanics, and biological responses, which appoint them extremely pertinent for a broad variety of applications. Besides the unique properties of hydrogels, the limited mechanical strength of soft gels restricts their utility for load-bearing applications. Reinforcing mechanically weak hydrogels with carbonaceous nanoallotropes is the utmost requirement to enhance interfacial interlocking and strengthening. This review covers the major proficiencies of the hydrogels, with wide attention on the effect on the performance of hydrogels when blended with the carbon nanoallotropes. The review sheds light on how the fabrication of hydrogel with carbonaceous nanoallotropes can alter the mechanical, tribological, and biological properties and thus the range of applications from biomedical to cosmetics to environmental. This report provides highlights on the in-silico studies on diverse hydrogels and carbonaceous materials along with facilitating a concise interpretation of the role of theoretical tools particularly, the DFT approach. The review accomplishes in-silico design and characterization of hydrogel composites for the structural/geometrical, energetics/stability (binding/adsorption energy and interfacial/bonding interactions between the hydrogels and nanoallotropes of carbon), and electronic (charge transfer, HOMO-LUMO, the total density of states, etc.) features along with succinct deliberation of their potential applications. It is anticipated from this review that the readers will acquire an ample depiction of the expansive opportunities of hydrogels grafted with inimitable carbon nanoallotropes to make differences in experimental and theoretical progress across various properties and applications.