Calligraphy in Islamic architecture, beyond its decorative function, operates as a visual language that consolidates cultural memory, reinforces political–religious legitimacy, and organizes meaning within sacred spaces. Focusing on funerary architecture, this study seeks to demonstrate how inscriptions transcend mere aesthetics to become discursive and spatial texts. The central question addressed is how calligraphy in Islamic mausoleums functions as a visual-discursive language in shaping collective memory and symbolic legitimacy. The research adopts a qualitative and interpretive approach, employing visual–spatial discourse analysis across three exemplary cases: the Dome of Soltaniyeh (Ilkhanid, 14th century), the Gur-e Amir Mausoleum (Timurid, 15th century), and the Mausoleum of Rumi in Konya (Seljuk–Ottoman, 13th–16th centuries). The theoretical framework draws upon the concepts of cultural memory (Halbwachs, Assmann, Nora), the discourse of space and power (Foucault, Lefebvre), and symbolic capital (Bourdieu). The findings reveal that in Soltaniyeh, calligraphy in Thuluth and Naskh scripts served to affirm the Shi‘i identity of the Ilkhanids; in Gur-e Amir, inscriptions redefined Timur’s image from a military conqueror to a spiritual memory; and in Rumi’s mausoleum, Qur’anic verses and mystical poetry inscribed in Nasta‘liq and Ta‘liq scripts created an experiential and spiritual atmosphere. The study concludes that funerary calligraphy functions simultaneously at three levels: as cultural memory, as spatial-discursive practice, and as symbolic–social capital. In this way, calligraphy emerges as an effective medium for legitimization, identity formation, and the reproduction of cultural memory in Islamic architecture.