The sensitivity of high strength steels (HSS) to hydrogen embrittlement is well established. Cracking is likely to occur even at very low hydrogen content. Hence, it is important to develop new and very sensitive methods (e.g., with high lateral resolution) to study the sources of hydrogen, the distribution of hydrogen in the metal and the mechanisms of hydrogen interaction with microstructural defects and with the surface oxide. This report reviews the application of the localized electrochemical techniques such as Scanning Kelvin Probe (SKP), Scanning Vibration Electrode Technique (SVET), Local Electrochemical Impedance Spectroscopy (LEIS), and Scanning Electrochemical Microscopies (SECM) to study the hydrogenation of austenitic stainless steel, HSS and galvanized HSS under different experimental conditions. For example, SKP can detect 0.01 ppm of atomic hydrogen. This low detection limit is based on the nanoscale interaction of emerged hydrogen with the surface oxide film. Hydrogen diffuses and decreases the Volta potential of the surface at the locations of the emerging due to the reduction of Fe3+ species in the oxide film. It enables real time monitoring of the reduction of oxide film that is related to the failure of the steel passivity. SKP measurements are carried out in air and provide information on the relative hydrogenation due to atmospheric corrosion. In the case of LEIS, hydrogen interacts with surface oxide increasing the capacitance and decreasing the resistance of the film that can be monitored in a water electrolyte. SECM is able to map hydrogen distribution in the electrolyte in the vicinity of the steel surface. Advantages and disadvantages of the different techniques are discussed. The combined effect of mechanical stress and the hydrogen on the steel passivity is also under the scope of this review.