Financial development and digital infrastructure have become key determinants of economic growth in the modern global economy. The rapid advancement of digitalization and the deepening of financial systems have significantly transformed growth dynamics, particularly in developing countries. In this context, this study examines the causal relationships between financial development, digital infrastructure indicators, and economic growth in Türkiye over the period 1993-2023. The Fourier ADF unit root test is employed to determine the stationarity properties of the variables. The causal relationships among the variables are analyzed using the Fourier Toda-Yamamoto causality approach, which provides robust inference in the presence of different integration orders and structural breaks. Additionally, Fourier terms are incorporated into the model to capture potential smooth structural changes. The empirical findings reveal statistically significant causal relationships running from financial development and digital infrastructure indicators to economic growth. In particular, digital indicators such as internet usage and mobile cellular subscriptions exhibit strong causal relationships with economic growth. Furthermore, a causal relationship from financial development to economic growth is also identified. The results indicate that digitalization and financial deepening play a decisive role in shaping economic growth dynamics in Türkiye. These findings suggest that policies aimed at strengthening digital infrastructure and enhancing the efficiency of the financial system can contribute to economic performance.