Gel-nanocomposites are rapidly emerging functional advanced materials having widespread applications in materials and biological sciences. Herein, we review syntheses, properties, and applications of various gel-nanocomposites assembled from different metal-based nanoparticles or nanocarbons fullerene, carbon nanotubes (CNTs), and graphenes with tailor-made supramolecular (small molecular) or polymeric physical organogels and hydrogels. Dynamic supramolecular self-assembly of gelators prove to be excellent hosts for the incorporation of these dimensionally different nanomaterials. Thus, gel-nanocomposites doped with preformed/in situ synthesized nanoparticles show magnetic or near-infrared-responsive, catalytic or antibacterial properties. Fullerene-based gel-nanocomposites show applications in organic solar cells. Gel-nanocomposites based on CNTs and graphenes and their functionalized (covalent/noncovalent) analogues find interesting properties including electrical conductivity, viscoelasticity, thermal robustness, magnetic, phase-selective, redox and near-infrared radiation sensitive properties. We present appropriate rationale to explain most of these phenomena at the molecular level, which provide useful perspectives for future designs and new spin-offs. Finally, a possible outlook is projected for the design and syntheses of next generation multifunctional gel-nanocomposites, which could be achieved by increasing the complexity of the system upon adding selective nanomaterials with desired properties in a multicomponent mixture following a de novo design in order to take advantage of their individual properties.