The study re-examines the determinants of financial sector development in Nigeria. The Autoregressive Distributed Lag (ARDL) model was used as the estimation technique using quarterly data from 2012Q1 to 2022Q4. The study found that corruption, financial innovation, trade openness and inflation are the determinants of financial sector development in Nigeria. Corruption and trade openness were found to have a negative impact on financial sector development whereas financial innovation and inflation had a positive impact. The study therefore recommends among others, the strengthening of anti-corruption measures by focusing on enforcing anti corruption policies and enhancing transparency within the financial sector. It also recommends that financial innovation should be promoted by encouraging technological advancements and the introduction of new financial products so as to enable the financial sector adapt to changing economic conditions.