In the current thesis, we would like to address two of them. First, in many existing studies, administrative regions are used in terms of spatial units. They might differ from functional regions as economic boundaries do not always coincide with geographical or administrative boundaries (Magrini 2007). In this study, we would like to focus on functional regions and compare the results provided by NUTS-2 regions. Second, in the calculation of HDI, the majority of studies have used traditional income, education, and health indicators. However, we think that employment and the labor market is a very crucial aspect that employment/unemployment directly points to a welfare loss. Hence, we would like to incorporate the employment rate in the calculation of HDI analysis. We focused on 26 NUTS-2 Turkish regions and functional 26 regions detected by Burak Beyhan's (2019) study. The period of the analysis is between 2009-2018. In terms of methodology, the explorative maps, Local and Global Moran’s I, Kernel Density estimations, and spatial panel regressions are employed. Our analyses revealed 4 main results. First, there are sizable differences in human development across regions in Turkey. Second, the level of disparities was observed as worse when functional regions are used instead of NUTS-2 regions. Third, convergence across regions in development is more evident and pronounced under functional regions whereas no/weak such pattern is observed for NUTS-2 regions. Four, the development disparities are observed in a spatially correlated manner. Keywords: Regional Development, Functional regions, HDI, Employment rate, Panel Regression analysis