Irrigation is considered an important factor for agriculture and food security. Knowledge gaps, however, still exist with regard to how farmers in Africa south of Sahara, including Nigeria, are using irrigation. Given the diverse agroecological and socioeconomic environment in countries like Nigeria, understanding the diverse patterns of irrigation use and their associations with household characteristics is important in designing how irrigation can contribute to the agricultural transformation. This report summarizes the typology of farm households and irrigators in Nigeria. We apply a cluster analysis method to the Living Standard Measurement Survey (LSMS)—Integrated Survey on Agriculture data and various secondary data. We also compare the costs and inputs used across different irrigation crops, as reported in Nigeria. Findings indicate that the three major irrigation systems in Nigeria are (1) labor-intensive diverted stream irrigation of rice, (2) supplementary irrigation of coarse grains and legumes using groundwater, and (3) dry season irrigation of vegetables. Each crop is irrigated during a specific season and using a specific water source and irrigation system. Farmers’ choice of irrigation system tends to depend on many factors. For example, in the South, tractorization is often a necessary precondition for rice irrigation. In the North, intensive irrigation of rice and vegetables may make sense only if labor is cheap, whereas irrigation of sorghum and legumes is supplementary and may not affect farm households’ behaviors. Although more rigorous studies are needed in the future, observed patterns of irrigation use in Nigeria indicate that the policies aiming to raise agricultural productivity and to develop the value chains of key crops may need to be based on an understanding of why irrigation is used in specific ways in different systems and of what the key constraints in scaling up such systems in other locations are.