This paper explores the striking similarities in the dome interiors of the Hagia Sophia and the Süleymaniye Mosque, two iconic structures in Istanbul. Despite their divergent cultural origins and the passage of centuries, these buildings exhibit remarkable resemblances in their interior decoration, particularly in their domes and pendentives. The study employs a diachronic comparative analysis, combining literary research and visual analysis to delve into the cultural, political, and religious contexts that shaped these architectural masterpieces. By examining historical records and visual evidence, the paper uncovers the shared elements, influences, and divergences in the interior decoration. This interdisciplinary approach sheds light on the interplay between art, architecture, and religious beliefs, offering valuable insights into the enduring significance and transcendent nature of these structures.