This chapter examines how sustainable architecture and building practices are shaping Nigeria’s cities. It emphasizes the importance of designing and constructing buildings that respond to the country’s climate, culture, and social realities while protecting the environment. Sustainability is promoted through energy efficient technologies, locally available materials, and green construction methods that support affordable, durable, and comfortable buildings. The research explores how environmentally responsible architectural choices influence urban development in Nigeria, focusing on construction materials and methods and their suitability to local needs. Data were gathered through literature reviews, building site visits, and interviews in Abuja, Maiduguri, Kano, Enugu, Port Harcourt, and Lagos. Findings show that Nigeria possesses sustainable traditional materials, including earth, laterite, bamboo, timber, and compressed stabilized earth blocks. However, their adoption remains limited by weak policy enforcement, inadequate awareness, technological challenges, limited technical expertise, and high initial costs. The study identifies passive design strategies, renewable energy, rainwater harvesting, green roofs and walls, material reuse, modular construction, prefabrication, and circular economy principles as effective approaches to reducing carbon emissions, conserving resources, minimizing waste, and improving environmental outcomes. Sustainable building practices can also strengthen urban resilience by reducing urban heat islands, improving indoor air quality, supporting biodiversity, promoting mixed use development, creating green construction employment, improving public health, and enhancing long term housing affordability. The chapter recommends stronger institutions and regulations, regular building code updates, increased investment in research and innovation, financial incentives for green initiatives, and stronger collaboration among government, universities, professional bodies, and private companies to promote resilient, inclusive, and resource efficient Nigerian cities.