Under the influence of accelerated digitalization, the financial industry is experiencing dramatic changes due to changing customer behaviour, growing expectations, the emergence of new distribution channels and the emergence of innovative products and services. This paper investigates the effects of digital transformation on the accessibility, depth, efficiency, and stability of financial institutions and markets amidst accelerating digitalization. Utilizing panel data from selected OECD countries spanning 2006 to 2021, the study constructs a Digital Transformation Index (DTI) based on ten indicators. This index serves as a proxy for digital transformation. Results indicate varied impacts across different facets of financial development. Increased digitalization leads to a decline in the financial resources provided to the private sector by domestic money banks as a share of GDP, and to a lower share of total assets relative to GDP. Digital development also has a negative impact on the number of commercial bank branches per capita. On the other hand, the positive impact of digitalization on the efficiency of financial institutions is undisputed, as the DTI index has a positive effect on a bank’s non-interest income relative to total income and a negative effect on a bank’s operating costs relative to total assets.