Subjective well-being (SWB) is integrative, but supporters of authentic happiness have criticized it as overemphasizing emotions and difficult to interpret eudaemonic well-being. The primary reason is that the theoretical basis of emotional perspective has not been fully considered, resulting in several research gaps. This study aims to provide evidence for integrative SWB and fills the research gaps by analyzing the antecedent appraisal mechanisms leading to ultimate happiness in tourism using qualitative grounded theory. The following results are observed. (1) The appraisal leading to ultimate emotional happiness involves eudaemonic well-being. (2) The dominant factors include attention activation, interestingness, goal relevance, goal realization, and group attribution, and the antecedent feeling is flow experience. This study is innovative because it verifies the existence of integrated SWB in tourism, provides a rigorous application of the appraisal theory in tourism, and is the first study considering the appraisal of a time-specific and retrospective tourism emotion.