The miniaturization of integrated circuits using top-down fabrication has reached a limit set by deleterious quantum effects, such as tunneling, which start to appear at the scale of a few nm. Bottom-up fabrication with molecular electronic components offers a fascinating alternative, as well-designed single-molecule devices can exploit quantum effects instead of being limited by them. Linear acenes and carbon nanobelts (Figure ) are attractive candidates for this purpose because they demonstrate efficient charge transport (G ≈ 0.1 G0, where G0 is the conductance quantum). Their porphyrin analogues, the edge-fused porphyrin nanoribbons l-PN (Figure ) show similarly high conductance (G ≈ 0.1 G0), but over longer distances, as well as exceptionally low energy gaps and quantum interference effects. These properties are attributed to extensive delocalization of the electronic wavefunction. In this work, we explore electronic delocalization in edge-fused porphyrin nanobelts 9 c-PN (where N is the number of porphyrin units, Figure ) computationally, with the goal of guiding future synthetic exploration.