The purpose of this investigation was to deepen understanding of how farmer personal features and farm characteristics affect the profitability of backyard fish farms in south- south Nigeria. In order to achieve the aim of the study, primary data were collected on farmer and farm-based variables, using questionnaire from randomly selected fish farmers in 2018. Nested regression models were estimated to evaluate the separate and combined effects of farmer and farm characteristics of profitability. The results indicates that the mean age was 41 years, 84.4% of them were male and majority (90.0%) had secondary education and above. The mean farming experience was 8 years with mean household size of 9 persons. The findings revealed that backyard fish farming was profitable with a total revenue of N2, 233,800 (6111.63 USD), a total cost of N1, 404,280 (3842.08 USD) with a net income of N829520 (2269.55 USD) and BCR of 1.59. The benefit-cost ratio (BCR) of 1.59 implies that every N1.00 invested in backyard fish farming will yield additional income of N0.59k. The result shows that backyard fish farms profitability responds positively to farmers personal characteristics (age, years of experience, gender, education and family size). Farmer personal characteristics significantly and jointly explained 37% variation in profitability. Farm characteristics (stocking density and fertilizer) significantly and positively (p<0.05) influenced profitability of backyard fish farms. The most important cost factors that negatively affected profitability are unit cost of feeds, fingerlings and water supply. It was recommended that backyard fish farmers should increase stock size, acquire more education as human capital development and form cooperative societies to address the constraint of inadequate access to credit facilities.