Potassium perylene-3,4,9,10-tetracarboxylate was exploited as a new organic anode for potassium-ion batteries, exhibiting two-electron redox behavior and a theoretical capacity of 93 mA h g-1. After optimization, the K4PTC electrode showed an average of 50 mA h g-1 over 2500 cycles at a current density of 0.5 A g-1.