This article reports the development, validation, and correlates of a self-report measure of boredom proneness. The 28-item Boredom Proneness (BP) Scale demonstrates satisfactory levels of internal consistency (coefficient α = .79) and test-retest reliability (r = .83) over a 1-week interval. Evidence of validity for the BP is supported by correlations with other boredom measures and from a set of studies evaluating interest and attention in the classroom. Other hypothesized relationships with boredom were tested, with significant positive associations found with depression, hopelessness, perceived effort, loneliness, and a motivational orientation. Additional findings indicate boredom proneness to be negatively related to life satisfaction and autonomy orientation. The relationship of boredom to other affective states is discussed, and directions for future research are outlined.