Medieval mappaemundi, world maps, have been primarily studied by geographical and cartographical scholars as visual representations of medieval conceptions of geographical space or as an encyclopedia of biblical history. Recently, however, art historians have begun to engage with the visual aspect of medieval maps and have questioned how the viewer approached and used such works. This essay contributes to the development of an art-historical understanding of medieval cartography by investigating two maps found within the thirteenth-century manuscript known as the Psalter Mappaemundi. I argue that the two maps of the Psalter Mappaemundi operate as an interactive media, analogous to other forms of illuminated psalter manuscripts, to aid the beholder in devotional practices. To explore the performative aspects of the Psalter Mappaemundi, I place the world maps within the devotional context of a psalter and connect it to medieval concepts of vision. I, then argue that the formal aspects of the maps, including their structural formatting, imagery, and color were strategically designed to aid in devotional memory practices or in a mirrored pilgrimage. These medieval mappaemundi are not merely representations of the world created by medieval cartographers, but rather are illustrations that enable interaction between object and beholder during devotional practices.