Despite efforts to promote sustainable development planning, programmes and projects in Nigeria, the process has achieved little success due to certain limitations. There have been cases of abandoned projects, vandalism, theft, corrupt and fraudulent practices, but the significant of it all is the neglect of indigenous people, multiculturalism and noninclusiveness in development planning. It has been observed that the development of Port Harcourt City is limited to few ethnic groups located within the State capital. This has initiated a pause in the pace of development in the city due to inequality, ethnic interest, injustice, and under-development of many areas. Most operating firms are foreign and their interests are centered at making profits and not developing indigenous people and their environment. There is reduction in human capacity building and, lack of acquisition of new skills among the people. The State development plans and execution lacked participation of other natives within the State. In an attempt to addressing development planning issues, this paper buttressed the fact that Port Harcourt City can go a long way in promoting development planning by adopting indigenous people, multiculturalism and inclusiveness in Port Harcourt City development planning. The paper, therefore, focused on conceptual analysis of multiculturalism, indigenous people and development, through inclusiveness approaches to solve challenges of development in Nigeria. The paper suggested amongst others that the people should identify sustainable development programmes and projects and promote them through multiculturalism and inclusiveness of indigenous people.