This study examines the relationship between ownership structure and dividend policy in Nigerian deposit money banks (DMBs), focusing on managerial, institutional, and foreign ownership. The study aims to assess the impact of these ownership types on dividend payout decisions while addressing dynamic effects and endogeneity. The research objectives are: (1) the effect of managerial ownership on dividend payout policy, (2) the impact of institutional ownership, (3) the relationship between foreign ownership concentration and dividend payouts, and (4) the influence of firm-specific factors such as firm size. A quantitative research design was used, analyzing secondary data from the audited financial reports of 10 Nigerian DMBs listed on the Nigerian Stock Exchange (NSE) from 2015 to 2024. A panel data methodology with Generalized Method of Moments (GMM) was employed to account for dynamic effects and endogeneity. The sample size consisted of 10 DMBs, selected through purposive sampling. Descriptive statistics, Pearson’s correlation, and System GMM were used for data analysis. Findings reveal that institutional ownership positively affects dividend payouts, while managerial and foreign ownership have negative effects, possibly due to entrenchment and preference for retained earnings. Firm size is positively correlated with dividend payouts, indicating that larger banks tend to pay higher dividends. This study contributes to understanding how ownership structures influence dividend policies in emerging markets and offers insights for policy makers and investors. It recommends enhancing governance mechanisms in Nigerian DMBs to align management’s interests with those of shareholders.