We have demonstrated that micropipette electrochemical cells with radii between 2 and 10 𝜇𝜇m can be used to assess whether a lipophilic basic compound is suitable for the study of PT kinetics at the liquidliquid interface. By switching the position of the electrolyte solutions between the inside and outside of the pipette, asymmetric transport limitations in the cyclic voltammetry revealed that DPP facilitates PT via an interfacial mechanism at an aqueous electrolyte pH of 1. Finite-element simulations of facilitated ion transfer models reveal that both sequential and direct mechanisms may contribute to the measured current, but that increasing the partition coefficient of the simulated proton acceptor reduced the contribution of the sequential current to the overall current response as it lowered the maximum potential-independent rate of neutral phase transfer. The kinetic rate constants of the neutral phase transfer step also affect whether proton transfer will occur via a direct or sequential mechanism, however within the range of physically reasonable values, PT is not likely to proceed through a sequential mechanism. Via nanopipette voltammetry we collected partially activation-controlled PT data which was fit to a model for the extraction of fundamental kinetic parameters k 0 and α. The large value of the obtained standard rate constant > 3 cm/s points to interfacial ionic processes being anomalously fast given the need to exchange solvent molecules around the ion during transit. We hypothesized that the transferring proton must be guided along its reaction coordinate by a gradient in equilibrium solvation states, though further experiments and modeling would be needed to support this claim. Nevertheless, ultrafast ion transfer at the liquid-liquid interface stands as a promising model system to study ion-solvent interactions in interfacial electrochemical systems in the absence of the usual defects inherent to electrode-electrolyte interfaces. Understanding more about why ion transfer at the ITIES is so fast may yield new insight into ways to accelerate or catalyze ion transfer in systems where it is likely to be rate determining such as battery-type intercalation reactions and electrocatalysis.