This chapter explores ecological sustainability within the context of event businesses, emphasizing the critical role sustainable practices play in mitigating the ecological impacts associated with events, such as waste generation, pollution, resource depletion, and increased carbon emissions. It discusses the historical evolution and economic significance of events while highlighting their potential for negative environmental effects. The chapter introduces various eco-labels and sustainability certifications, including ISO 20121, APEX/ASTM, Austria’s Eco-label, Eco Logo, and BS:8901, which assist event planners in managing ecological impacts responsibly. The chapter also outlines key sustainable practices that event organizers can implement, such as energy-efficient strategies, sustainable transportation methods, waste reduction techniques, sustainable food consumption planning, and the integration of online or hybrid event formats to reduce travel-related emissions. Real-world examples, including the 21st UN Climate Conference in Paris, demonstrate effective implementations of these practices. The chapter concludes by advocating for comprehensive and collaborative sustainability planning involving all event stakeholders to enhance ecological responsibility.