Ionic Coulomb blockade (ICB) is an electrostatic phenomenon that appears in ionic transport through mesoscopic electro-diffusive systems (artificial nanopores and biological ion channels) and manifests itself as oscillatory dependences of the conductance on the fixed charge in the pore ( or on the external voltage , or on the bulk concentration ). ICB represents an ion-related counterpart of the better-known electronic Coulomb blockade (ECB) that is observed in quantum dots. Both ICB and ECB arise from quantisation of the electric charge and from an electrostatic exclusion principle and they share in common a number of effects and underlying physical mechanisms. ICB provides some specific effects related to the existence of ions of different charge (different in both sign and value) where integer is ion valence and is the elementary charge, in contrast to the single-valence electrons of ECB (). ICB effects appear in tiny pores whose self-capacitance is so small that the charging energy of a single ion becomes large compared to the thermal energy per particle ( ). In such cases there is strong quantisation of the energy spectrum inside the pore, and the system may either be “blockaded” against the transportation of ions or, in the opposite extreme, it may show resonant barrier-less conduction, depending on the free energy bias coming from , , or . The ICB model claims that is a primary determinant of conduction and selectivity for particular ions, and the predicted oscillations in conductance and an associated Coulomb staircase of channel occupancy vs are expected to be strong effects in the cases of divalent ions () or trivalent ions (). Some effects, now recognised as belonging to ICB, were discovered and considered earlier in precursor papers on electrostatics-governed conduction mechanisms in channels and nanopores. The manifestations of ICB have been observed in water-filled sub-nanometre pores through a 2D MoS2 monolayer, revealed by Brownian dynamics (BD) simulations of calcium conductance bands in narrow channels, and account for a diversity of effects seen in biological ion channels. ICB predictions have also been confirmed by a mutation study of divalent blockade in the NaChBac bacterial channel. Model Generic electrostatic model of channel/nanopore ICB effects may be derived on the basis of a simplified electrostatics/Brownian dynamics model of a nanopore or of the selectivity filter of an ion channel. The model represents the channel/pore as a charged hole through a water-filled protein hub embedded in the membrane. Its