© 2020 The physicochemical properties of a molecule-metal interface, in principle, can play a significant role in tuning the electronic properties of organic devices. In this report, we demonstrate an electrode engineering approach in a robust, reproducible molecular memristor that enables a colossal tunability in both switching voltage (from 130 mV to 4 V i.e. >2500% variation) and current (by ~6 orders of magnitude). This provides a spectrum of device design parameters that can be ¿dialed-in¿ to create fast, scalable and ultralow energy organic memristors optimal for applications spanning digital memory, logic circuits and brain-inspired computing.