This study examines the dynamics of ethnic coexistence and nation-building in Cameroon’s rapidly expanding urban centres, with particular focus on Douala and Yaoundé. Against the backdrop of Sub-Saharan Africa’s profound ethnic diversity, where 43% of global ethnic groups reside, the research investigates how multiculturalism shapes urban development and social integration. Cameroon’s 250+ ethnic groups navigating increasingly diverse urban spaces present both challenges and opportunities for inclusive city planning. The study analyses the emergence of pan-ethnic consciousness (such as Sawa and Bassa identities) as political responses to perceived marginalisation, and the constitutional entrenchment of “native/settler” distinctions in 1996. Through examining interethnic marriages, urban tribal organisations, and competing narratives of cultural versus political ethnicity, the research explores tensions between the “melting pot” ideal and persistent ethnic boundaries. It investigates whether urban centres are fostering a unified Cameroonian identity or reinforcing ethnic divisions. The findings aim to inform policies for harmonious multicultural coexistence and sustainable nation-building in Africa’s most ethnically diverse region.