The increasing difficulty in managing one's online personal data leads to individuals feeling a loss of control. Additionally, repeated consumer data breaches have given people a sense of futility, ultimately making them weary of having to think about online privacy. This phenomenon is called “privacy fatigue.” Although privacy fatigue is prevalent and has been discussed by scholars, there is little empirical research on the phenomenon. This study aimed not only to conceptualize privacy fatigue but also to examine its role in online privacy behavior. Based on literature on burnout, we developed measurement items for privacy fatigue, which has two key dimensions —emotional exhaustion and cynicism. Data analyzed from a survey of 324 Internet users showed that privacy fatigue has a stronger impact on privacy behavior than privacy concerns do, although the latter is widely regarded as the dominant factor in explaining online privacy behavior.