Frequently referred to as the Giant of Africa, Nigeria is growing slower than its population and large numbers of people are poor. With gross national income per capita of US$2,100 (in 2017; Atlas method, WDI), Nigeria is classified as a lower-middle-income country. It is richly endowed, has a relatively young, rural, and multiethnic population, and accounts for the largest economy and population in Africa. It has the potential to become an economic powerhouse through the effective management of its abundant resources, including plentiful agricultural land, marine fisheries, hydropower, oil and gas, unexploited deposits of minerals and metals, a young labor force, and a strong entrepreneurship culture. One-fifth of the population is in the middle class. However, significant poverty persists despite the government’s effort to reduce the high poverty rate. Measured according to the US$1.90-a-day per capita purchasing power parity poverty line, it is estimated that 42.8 percent of Nigeria’s population was living in extreme poverty in 2016. Poverty has been rising in rural areas and in the northern zones, while the situation in the southern zones has generally been improving. Nigeria needs more inclusive economic growth, so more people can exit from poverty, and the country can evolve into a society with a sizable middle class, a viable social contract between the government and the people, and peace and prosperity across the nation. A key development challenge in Nigeria revolves around economic growth, which has had a limited impact on reducing poverty and building shared prosperity. This Systematic Country Diagnostic (SCD) examines the challenges the government and people of Nigeria face in achieving the twin goals of poverty reduction and shared prosperity.