As concern for environmental sustainability increases, many firms are using green marketing to connect with environmentally conscious consumers. This conceptual paper examines how green marketing strategies contribute to customer loyalty by building authenticity and encouraging customer engagement. Using Signalling Theory and Relationship Marketing Theory, the study explains how genuine environmental claims help develop trust and reduce scepticism. It also shows how customer engagement, through cognitive, emotional, and behavioural involvement, converts trust into outcomes such as satisfaction, repeat purchases, and advocacy. The paper highlights the risks associated with greenwashing and offers practical insights for organisations seeking to design credible and effective green marketing practices.