In this paper, we present a study comprising two distinct stages to examine the extent to which metacognitive processes of decentering facilitate the emergence of self-transcendence experiences in everyday life (i.e., the frequency of self-transcendent emotions, flow proneness, and adopting an interconnected identity). In the course of conducting this research, the first stage ( N = 374) focused on assessing the structure and validity of the French version of the Metacognitive Processes of Decentering Scale (MPoD-t). Building on this, the second stage ( N = 294) examined the potential relationship between meditative practices and psychological decentering processes (i.e., meta-awareness, (dis)identification with internal experiences, and (non)reactivity to thought content) and explored whether these mechanisms explain the association between meditative practices and the experience of self-transcendent states. Overall, the results demonstrated satisfactory psychometric properties of the French version of the MPoD and provided enhanced insights into the distinct mediating roles played by various decentering components in the manifestation of self-transcendence experiences in daily life. Indeed, the findings revealed that the relationship between practice and the occurrence of self-transcendent emotions or flow was mediated by the meta-awareness component, while the association between practice and the development of an interconnected identity was explained by the (dis)identification with internal experiences component. The implications of these findings are discussed.