Ecotourism in the XXI century is becoming one of the most demanded and fastest growing areas of the tourism industry. This article is devoted to formation and development of ecotourism in the British Islands, as well as its organization and management. The authors have identified certain characteristics of ecotourism in the UK and Ireland. The tourism industry in the UK is highly developed and dynamic. The idea of development of ecological tourism reflects the need to create balance between economic benefits and environmental safety. The UK occupies one of leading places in terms of the development of rural and other types of ecological tourism. The development of green tourism and its regulation promotes not only competent work of all departments of the tourism industry, but also absolute transparency with a well-planned presentation of information. In Ireland, tourism is one of the most important and successful industries of the service sector and the economy as a whole. It makes a very significant contribution to socio-economic development of the country at the national and regional levels. Ecotourism is on an important place in the plans of the government. Ecotourism in Ireland refers to a wide range of tourist services and enjoys the support from the state. The country has established an effective system of organization and regulation of the sector, which successfully adapts to a qualitative change in the demand for tourist services.