Self-efficacy of balance, a psychological characteristic, may provide information regarding psychological risk factors for lower-extremity injury. Validated instruments to assess self-efficacy of balance do not currently exist. The objective of this study was to determine the face and content validity of the Self-Efficacy of Balance Scale (SEBS) for an adolescent population, as well as content validity, construct and convergent validity of the overall instrument. A series of panelists (n = 11) assessed proposed items for face and content validity for self-efficacy of balance. Construct and convergent validity were assessed with active college individuals (n = 74) and female high school basketball athletes (n = 57). Original items were revised to 21 items. Panelists validated both face and content validity of the SEBS. All items were assessed to have the construct of self-efficacy. Evidence of convergent validity supported the proposed construct of self-efficacy, and was found to be relevant to the physical functioning of a young, active population.