A theory of off-job reactivity to daily work stress which encompasses the prediction of levels of reactivity from specific daily occupational stressors and personality traits, and outcomes of state and trait off-job reactivity, is presented and empirically tested. Despite decades of research linking negative spillover to maladaptive work and non-work outcomes, multidimensional studies of manifestations of spillover are rare. While investigators have increasingly recognized that spillover correlates tend to be associated with greater off-job physiological stress responses (Meijman, Mulder, Van Dormolen,&Cremer, 1992), no attempt has been made to incorporate off-job reactivity to daily stress within a multidimensional framework of negative work to non-work spillover. The overarching goal of this dissertation is to develop a model of off-job reactivity to daily occupational stress, comprising cognitive, affective, and behavioral indicators of negative work to non-work spillover. An empirical study is presented in which 75 nurses (N = 75) reported their exposure to different categories of daily work stress and provided measurements of off-job reactivity and anticipated outcomes during their off-job time for four work days. Select personality traits, work characteristics, and trait-level outcome variables were measured via an at-home questionnaire prior to the daily survey period. Empirical validation was obtained for a three-facet, higher-order factor model of off-job reactivity. Negative interpersonal interactions and situational constraints were supported as daily stressor predictors of state off-job reactivity, while trait negative affect and abusive supervision were supported as predictors of this state-level outcome. Elevated off-job reactivity was associated with several maladaptive outcomes, including diminished subjective well-being, elevated work to non-work conflict, greater somatic complaint frequency, and reduced off-job recovery activity pursuit. Implications of these findings for theoretical models of work - non-work relationships, the relative contribution of predictors and outcomes of off-job reactivity, and practical applications of the results of this dissertation are discussed.