Adequate environmental health services are critical for human rights, health, and development, especially in the context of forced displacement. There are more than 70 million forcibly displaced persons worldwide, most in protracted situations, having been displaced for more than two years. Some live in camps or informal settlements, but most live in urban areas. Environmental health services are important in the transition from emergency response to sustainable development in these settings, but evidence on environmental health in displaced populations is disparate and of variable quality. We conducted a systematic scoping review of environmental conditions, exposures, and outcomes in protracted displacement settings; obstacles to improvement in environmental health services; and recommendations made for improvement. We included 213 publications from peer-reviewed and grey literature databases. Data were extracted on environmental health topics including water, sanitation, hygiene, overcrowding, waste management, energy supply, vector control, menstrual hygiene, air quality, and food safety. Most studies present data from low- and lower-middle income countries. Northern Africa and Western Asia and Sub-Saharan Africa are the most-represented regions. There is substantial evidence on water, sanitation, and crowding, but few studies report findings on other environmental health topics. Water-related disease, parasites, and respiratory infections are frequently cited and studies report that services often fail to meet international standards for humanitarian response. The most frequent obstacles and recommendations are institutional, political, or implementation-related, but few studies provide concrete recommendations for improvement. Our review compiles and characterizes the research on environmental health in protracted displacement. We recommend including displaced populations in international environmental health policy and monitoring initiatives, and bridging from humanitarian response to sustainable development by preparing for long-term displacement from the early stages of a crisis.