This study examined the relationship between corporate board interlocks and the financial stability of Deposit Money Banks (DMBs) listed on the Nigerian Exchange Group (NGX) for the period 2017–2024. The study specifically assessed the influence of Board Interlock Density, Board Busyness, Board Diligence, and Board Size on financial stability, measured by the Capital Adequacy Ratio (CAR). The research was anchored on Resource Dependence Theory, Agency Theory, and Stewardship Theory, emphasizing the role of inter-organizational links, board engagement, and oversight effectiveness in sustaining banking stability. The study adopted an ex-post facto research design using panel data extracted from the annual reports of ten (10) listed DMBs over eight years. Secondary data were analyzed using descriptive statistics, correlation analysis, and panel regression with the aid of SPSS (version 27). The results indicated that Board Diligence significantly enhanced financial stability, while Board Busyness had a positive but marginal effect. Conversely, Board Interlock Density and Board Size exhibited no significant influence on bank stability. It recommended that Nigerian banks should emphasize board attendance, engagement, and effective oversight to strengthen regulatory compliance and institutional stability. Furthermore, while interlocks can foster resource sharing, excessive cross-directorships should be managed to prevent over commitment and conflict of interest.