Functional Performance of Islamic Geometry in Mosque Design in Osogbo, Osun State

This research investigates the functional Performance of Islamic geometry in contemporary mosque design. It demonstrates how geometric principles go beyond ordinary ornamentation and focus more on functionality, such as environmental performance, cultural expression, spatial organization, and structural stability. It balances the visual identity, spatial arrangement, and environmental impacts with divine belief. To address this gap, this research uses a qualitative research methodology based on the principles of symmetry, repetition, tessellation, and proportionality. A qualitative method design was employed through literature review, case studies analysis of the following mosques: camlica mosque (Turkey), Education city mosque (Qatar), and Ilorin Central Mosque (Nigeria). This mosque showcases the strong use of Islamic geometry and how a modern, contemporary mosque blends with traditional Islamic architecture, from the early monumental to aesthetic innovation. The study is based on three key elements (environmental responsiveness, symbolic meaning, and spatial functionality), which reflect how Islam expresses its ideas through the use of shapes and patterns., Islamic geometry was used in analyzing every aspect of this study to explore different cultures and historical contexts, ranging from the early mosque to the modern contemporary mosques. This research also highlights the key challenges, including the high cost of construction, the lack of skilled craftsmen, and cultural misinterpretation, and suggests that to solve these problems, this study recommends improving education and training in geometric design, adopting cost-effective methods of construction, and that architects should collaborate more with historians for a proper understanding of Islamic geometry. This research concludes that Islamic geometry is not static and it evolves with time, and they are key part of mosque design and not just for aesthetic purposes but also to ensure functionality, sustainability, and to promote Islamic symbolic tradition.