The electrochemical characteristics of Mg₂Si in dilute NaCl over a range of pH values are presented. In this study, Mg₂Si was carefully synthesized to permit the collection of its anodic and cathodic potentiodynamic polarization response. Difficulties in producing bulk Mg₂Si means that such data remains scarce to date. Mg₂Si is an important intermetallic that forms in Al and Mg alloys containing silicon. In this work, the electrochemical response of Mg₂Si is interpreted (and contrasted) in the context of Al and Mg alloys that contain Mg₂Si, revealing that Mg₂Si is either a local anode or local cathode.