This study investigated the relationship between financial development and income inequality in ECOWAS nations from 1986 to 2023. ARDL / PMG non-linear panel approach was used in the study, which used secondary data from the World Development Indicators (WDI). The dependent variable is income inequality of the ten countries chosen to represent the ECOWAS in this study base on availability of data, they are: Ghana, Guinea, Senegal, Liberia, Mali, Niger, Nigeria, and Cote d'Ivoire. The explanatory variables include; real income, inflation, government spending financial sector development. The findings showed a strong long-term link between real income, inflation, government spending financial sector development, and income inequality in ECOWAS member states. The findings showed that real income had a favorable and considerable short-term impact on income inequality in all ECOWAS countries. On the other hand, inflation is negatively correlated with income inequality. Furthermore, there is a weak and inverse relationship between government expenditure and income inequality in ECOWAS countries. Income inequality and financial sector development are positively correlated. Based on the result of our findings the recommend that government of ECOWAS countries should create a good financial environment to enable the poor to reach a better life opportunity. For this, regulations that make financial resources difficult to access should be audited and access to capital should be facilitated. Thus, entrepreneurial activities may develop and productivity increases throughout the economy.