ABSTRACT: This study examines the direct and indirect effects of Capital Structure on firm value, with the Cost of Capital (CoC) serving as a mediator. Firm value reflects how effectively a company manages its resources and increases shareholder wealth, and an optimal Capital Structure the mix of debt and equity plays a crucial role in achieving this goal by affecting financial risk, CoC, and market perception. By minimizing the Weighted Average Cost of Capital (WACC), companies can enhance their market valuation. The research focuses on plantation companies listed on the Indonesia Stock Exchange (IDX), measuring Capital Structure using the Debt to Equity Ratio (DER). This analysis provides empirical evidence on how financing decisions influence firm value through CoC, offering practical insights for managers and investors in the plantation sector to develop effective capital policies that maximize corporate value.

KEYWORDS:  Capital Structure, Firm Value, Cost of Capital, Debt To EquityRatio, Plantation Subsector