Background Previous studies have not examined the state-level variations in health facility delivery in Nigeria. Because of the decentralised system, state governments have a huge role in decision-making and policy direction for each state. As such, it is important to disaggregate the data at state level to understand patterns and best performing states that can be exemplars for others. We address this gap by examining the sub-national variations in health facility delivery in Nigeria. Methods Data of 37,928 and 40,567 live births in the 2013 and 2018 Nigeria Demographic and Health surveys (NDHS) respectively were analysed in this study. NDHS employs a multistage sampling and is representative of both the country and each of the 36 states and Federal Capital Territory (FCT). We used descriptive statistics to examine the trend in health facility delivery in Nigerian states and presented the results using maps. Also, we used logistic regression analysis to examine progress in expanding access to health facility delivery across Nigerian states. Results The proportion of births delivered in health facilities increased from 35.8% in 2013 to 39.4% in 2018, representing a 3.6% increment. After adjusting for relevant covariates, women were 17% more likely to deliver in health facilities in 2018 than in 2013 surveys. However, progress in expanding access to health facility delivery was uneven across the country. While the odds of delivering in a health facility significantly increased in 13 of the 36 states and FCT, the odds reduced significantly in seven states and no progress was recorded in 17 states. Conclusion There was a slight improvement in access to health facility delivery in Nigeria between 2013 and 2018. However, progress remains uneven across the states with only 13 states recording some progress. Four states stood out, recording over a three-fold relative increase in odds of health facility deliveries. These states implemented maternal health care policies that not only made services free but also improved infrastructure and human resources for health. Thus, providing examples of what works in improving access to maternal health care services for other states to follow.