Two small organic molecules, namely potassium terephthalate (K2TP) and potassium 2,5-pyridinedicarboxylate (K2PC), were newly exploited as the highly efficient organic anodes in K-ion batteries. Both K2TP and K2PC exhibited the clear and reversible discharge and charge platforms in K-ion half cells, which were resulted from the redox behavior of organic para-aromatic dicarboxylates. The satisfactory and reversible specific capacities were realized in the K2TP- and K2PC-based K-ion cells, with average values of 181 and 190mAhg−1 for 100 cycles, respectively. The currently-obtained achievement of organic anodes could make a forward step for the further development of rocking-chair K-ion batteries. Potassium salts of para-aromatic dicarboxylates were initially exploited as the highly advanced organic anodes in K-ion batteries. And the usage of organic anodes could effectively avoid the risk of producing highly-reactive K metal. Display omitted •Para-aromatic dicarboxylates could be the organic anodes in K-ion battery.•Satisfactory rate and cyclic capability were achieved in K-ion battery.•Specific capacity of average ~190mAhg−1 was obtained for 100 cycles.