The aim of the study was to determine the relationship between budget deficit and economic growth in Nigeria was examined using data derived from Central bank of Nigeria annual bulletin and world bank website. Data used for the study were annual data covering the period of 1970 to 2024. The study examined the relationship using multiple regression and autoregressive distributed lag whilst various diagnostics and post estimation analysis were made. The outcome of the study confirmed that budget deficit have positive effect on real GDP and hence significantly improve economic growth in Nigeria. Based on findings the study recommends that the efficiency of public spending needs to enhanced in Nigeria. This involves a more efficient allocation of deficit spending among optimal sectors in the economy. The extensive effect of budget deficits on the economy also requires that fiscal sustainability be ensured over time in Nigeria. The medium-term fiscal framework that forms the foundations of national budget need to be fully implemented in each budget cycle. Regular fiscal audits and transparent budgeting can ensure deficits remain sustainable while delivering economic benefits. The study further recommends that to optimize economic growth, policymakers need to strategically use fiscal deficits to boost GDP.