This study was motivated to examine the relationship between Nigerian public debt and domestic investment from 1990 – 2023. The general objective is to examine the extent to which public debt affect Nigerian domestic investment while the specific objectives are to investigate the extent to which Domestic Debt, External Debt, Debt Servicing and Deficit Financing affect domestic level of investment in Nigeria. Time series data were sourced from Central Bank of Nigeria Statistical Bulletin. Domestic investment was modeled as the function of Domestic Debt, External Debt, Debt Servicing and Deficit Financing. Ordinary Least Square Method of Analysis was used to examine the relationship between the variables. Findings from the regression results reveal that Domestic Debt and External Debt have positive and significant relationship with Nigerian Gross Level of investment while Debt Servicing and Deficit Financing have positive but insignificant effect. The study conclude that Public Debt have significant relationship with Nigerian Gross Level of Investment. It therefore recommends that policies should be device and the investment environment well managed to enhance domestic level of investment in Nigeria.