Phase selection for traveling wave fault detection systems is disclosed herein. Intelligent electronic devices (IEDs) may be used to monitor and protect electric power delivery systems by detecting and acting upon traveling waves. A phase of the electric power delivery system may be selected based on the relative polarity of the traveling waves detected. The amplitude and/or polarity of the selected phase may be compared with the amplitudes and/or polarities of the other phases to determine a fault condition. For instance, the IED may determine a single-phase-to-ground fault based on the relative polarities and magnitudes of the detected traveling waves, send a protective action to the identified faulted phase, and/or continue to monitor the system for a continuation of the event or identification of a different event, such as a three-phase fault, using incremental quantities.