This study examined financial sector development and original sin in Nigeria financial market. Time series data was sourced from Central Bank of Nigeria Statistical Bulletin from 1990-2023. Original sin measured by Nigeria external debt per exchange rate, Capital market development as market capitalization to gross domestic product, Foreign exchange market as variation in naira exchange rate per US Dollar, banking sector development as percentage total bank assets to gross domestic product, money market development as insurance total assets to gross domestic product, Money market development as value of money market instrument to gross domestic product. The study employed descriptive statistics and multiple regression models to estimate the relationship that exists between the dependent and independent variables. The null Hypotheses (H0) were tested at 0.05 level of significance, Ordinary Least Square (OLS), Augmented Dickey Fuller Test, Johansen Co-integration test, normalized co-integrating equations and parsimonious vector error correction model were used to conduct the investigations and analysis. The study found that 57.0% variation on original sin can be traced and explained by variation on the independent variables as formulated in the regression model. However, the F-Statistics and the F-probability justifies that the model is significant and adequate in explaining variation on the dependent variable. The β coefficient shows that capital market development have negative effect on original sin, foreign exchange market have positive effect on original sin, banking sector development have negative effect on original sin, insurance sector development and money market development have positive effect on original sin. From the findings, the study concludes that the independent variables determine positively and negatively original sin in Nigeria. We recommend that the need for policies to deepen the capital market as this can cushion the effect of the negative effect of external borrowing and domiciled in Nigeria currency rather than international currency. There should be institutionalized policies to enhance the value of the naira against other international currencies as this can reduce the pressure of exchange rate variation in international debt and international monetary environment. Public expenditure should be directed to the productive sector of the economy as this can enhance the productive capacity of the economy and reduce the negative effect on balance of payment and other macroeconomic variables. Policies should be advanced to reduce external borrowings; this can reduce the debt burden and reduce the incidence of original sin in the financial market.