This study investigates whether the issuance of corporate green bonds affects firms’ market value of equity, using a global panel of green bond issuers from 2013 to 2022. Employing a modified Ohlson (1995) valuation framework, the propensity score matching approach, and a staggered difference-in-differences design, we find that green bond issuance significantly increases equity valuation. The effect is stronger for firms with lower information asymmetry, stronger institutional ownership, and reduced ESG-related risk exposure, suggesting that transparency, governance, and environmental credibility mediate the valuation impact. The effect is also more pronounced when green bonds are certified by the Climate Bonds Initiative (CBI) and when the use of proceeds is explicitly linked to environmental objectives, underscoring the importance of credible commitment. Subsample analyses reveal that the valuation effect varies across countries with different disclosure environments and across firms with varying ESG profiles. Robustness checks, including excluding the COVID-19 period, using alternative matching methods, and controlling for firm fixed effects, confirm the validity of our findings. Our results highlight that green bond issuance enhances shareholder value, particularly when embedded in supportive institutional and disclosure contexts, contributing novel insights to the literature on sustainable finance and equity pricing.