This study examines the relationship between tourism and the environment, highlighting the importance of ecological sustainability in the tourism industry. Tourism is a service industry that directly sources its raw materials from nature, exerting significant pressure on the environment. Developing and underdeveloped countries, in particular, view tourism as a tool for economic development while ignoring environmental and sociocultural sustainability. This situation negatively affects biodiversity, disrupts the ecological balance, and leads to the deterioration of cultural heritage. The study explains how sustainability has gained importance through international forums and conferences. The foundations of sustainable development were laid by the 1972 Stockholm Conference and the 1987 Brundtland Report. Tourism was addressed within the framework of sustainability with the United Nations Conference on Environment and Development (UNCED—Rio Summit) held in 1992. Sustainability in tourism requires a balanced approach to economic, environmental, and sociocultural dimensions. Additionally, the study details eco-label practices (such as the Blue Flag, Green Globe, Green Key, and ISO 14001) developed to support ecological sustainability in tourism and emphasizes their importance in protecting the environment and providing a competitive advantage to businesses. The study reveals that ecological sustainability practices offer positive outcomes for the tourism industry, such as cost advantages, resource conservation, and improved corporate image.