This study examines the link between financial sector deepening and economic growth in Nigeria using the financial time series methodology. Time series data on real gross domestic product (proxy for economic growth), financial sector credit, financial sector liquidity and financial market capitalization (proxy for financial sector deepening) were obtained from Central bank of Nigeria statistical bulletin and Nigeria exchange group fact sheet for 61 years (1960-2021). Descriptive analytical tools were used in analyzing the data. The analyses shows that from 2005-2020 the financial sector credit in Nigeria increased significantly above 20%, this growth is as a result of stability and security attained following the war on terrorism and increase in investments in the agriculture and private sector and also due to post election calm which is leading to the investors’ confidence and stability in business prospects thereby expanding the economy leading to more demand to the loan products of the banks in turn increasing financial sector credit base while financial market capitalization trend fluctuated all through 1995 to 2020, this implies unstable trend in Nigerian financial market capitalization and instability of banking industry and financial institutions in Nigeria. Between 2008 and 2010, the Nigerian economy suffered a sharp contraction. This was followed by another period of rapid growth between 2011 and 2014 during which the economy grew at an average rate of 7% per year. In 2016, the Nigerian economy was hit by its first recession in over two decades, with the GDP contracting by 1.6%. The recession was worsened by the sharp decline in global oil prices in 2014.