The study focuses on the impact of Population growth rate on Unemployment rate in Nigeria. While the specific objectives are to examine the causal effects between population growth rates and unemployment in Nigeria; ascertain the relationship between population growth rates and unemployment in Nigeria; and investigate the impact of population growth rate on unemployment in Nigeria.The source of data for this study is secondary sources and they were mainly from National Bureau of Statistics and Central Bank of Nigeria Statistical Bulletin. The analyses involved; descriptive statistics, graph and trend analysis. In addition, Granger Causality test was carried out to determine the direction of causation between Unemployment Rates (UNEMPR), and Population Rate (PGR), the Autoregressive Distributed Lagged (ARDL) and the Error Correction Model (ECM) were used in the analysis. From the result of causality test it is established that there is causal relationship between Population Growth Rate (PGR) and Life Expectancy in Nigeria (LEN). From the regression result there is a strong relationship between Unemployment Rate and the Independent Variables (Population Growth Rate (PGR), Life Expectancy in Nigeria (LEN) and Per Capita Income (PCY) both in the long and short run. Therefore, the study recommends that government should adopt a mechanism like family planning program and migration control in order to control population growth and reduce unemployment rate since the population rate increase the level of unemployment in Nigeria.