Numerous verses in the Holy Quran are considered to refer to the doctrine of Mahdism (al-Mahdawiyyah), even though the name of Imam al-Mahdi (may God hasten his reappearance) is not explicitly mentioned in any of them. One of the most significant of these verses is the Verse of Istikhlāf (Quran 24:55), which stands out as a preeminent text concerning the future of religious governance. Nevertheless, Imami and Sunni exegetes differ regarding its referent (miṣdāq). The central problem of this study is to elucidate the semantic indication of the Verse of Istikhlāf and examine its relationship with the doctrine of Mahdism. The pivotal question is: On what exegetical (tafsīrī) and narrational (riwāʾī) foundations does the indication of the Verse of Istikhlāf regarding Mahdism and the global government of Imam al-Mahdi rest? Adopting a descriptive-analytical method and a rational-textual (ʿaqlī-naqlī) approach, this library-based study examines the key concepts of the verse, including istikhlāf (divine succession), tamkīn al-dīn (establishment of religion), and tabdīl al-khawf (substitution of fear with security), and comparatively evaluates the viewpoints of the Imami and Sunni schools of thought. The findings demonstrate that the absolute nature of the divine promise, the complete realization of the establishment of religion, and the comprehensive stabilization of security align more consistently with the doctrine of Mahdism. Consequently, in its ultimate horizon, the semantic scope of the verse is most fully realized in the era of the advent (ẓuhūr) of Imam al-Mahdi