The study examines the causal relationship between financial development and economic growth through trade openness for the leading ASEAN countries (Indonesia, the Philippines, Malaysia, Singapore, Thailand, and Vietnam). The study employs a panel data for the period of 25 years spanning from 1995 to 2019 for the six countries, yielding a balanced panel of 150 observations. Fixed effect model (FEM) and random effect model (REM) are used for the panel data, following the Hausman test performed for model selection. The trivariate Granger causality test is also used to check for possible relationship between the variables. The results show that REM is chosen based on the Hausman test result, suggesting that the trade openness has a positive association with growth whereas the financial development is positively, but insignificantly associated with growth. The reason for this is that the financial development and economic growth may be related to each other. The results are, then, further explored and confirmed by the causality test. That is, the financial development and the economic growth, through the trade openness, are found to have bidirectional positive relationships. This implies that there would be shortcomings when ignoring the presence of trade openness, which positively impacts the relationship between finance and growth.