ABSTRACT Research Question/Issue This study investigates the impact of board networks with previous green bond issuers—hereafter referred to as green networks—on the propensity of green bond issuances relative to conventional bonds across 45 economies. Research Findings/Insights The analysis provides robust evidence that firms with boards embedded in green networks exhibit a greater propensity to issue green bonds as opposed to conventional bonds. The effect is particularly pronounced for firms that obtain favorable green bond related information via their green networks and for those firms motivated to strengthen their environmental reputation. These findings suggest that board green networks function as an important mechanism for information diffusion and for signaling environmental commitment, thereby fostering the spillover of green financing practices across firms. Theoretical/Academic Implications Grounded in resource dependence and social capital theories, the study highlights the critical role of board‐level networks in shaping financing choices. Specifically, board green networks help mitigate information asymmetry and signal environmental reputation. Practitioner/Policy Implications The findings on green networks have direct implications for both corporate practice and public policy. Firms can leverage these networks to learn from peers' experiences, reducing risks in their own bond issuance. Policymakers could support this process by facilitating network‐building and creating platforms for sharing best practices in green bonds and other sustainability initiatives. Strengthening transparency in environmental disclosures could further stimulate green bond issuance by reinforcing the credibility and spillover of such practices across firms.