Electrochemistry is the chemistry of electrons and charge transfer. For a molecular level understanding one would like to probe the dynamics of electron transfer at the electrochemical interface on all relevant time scale. While conventional electrochemical characterization methods such as impedance spectroscopy are very useful in sampling “slow” dynamics, they are not fast enough for processes such as interfacial electron transfer or solvent reorganization. In this study a novel optoelectronic technique has been developed combining femtosecond lasers and conventional electrochemical electronics to characterize the birth and ultrafast structural evolution of solvated electrons at the gold/water interface. Transient spectra with a time resolution of 50 fs reveal novel aspects of the properties of solvated electrons at the interface, like trapping in a “hot state” and its subsequent evolution. The technique will enable a better understanding of hot electron-driven reactions at electrochemical interfaces.