In 2019, 30,000 people were forced to leave their homes due to conflict, persecution, and natural disaster each day. Eighty-five percent of refugees live in developing countries, and they often face underfunded and inadequate environmental health services. Many displaced persons live in camps and other temporary settlements long after the displacement event occurs. However, there is little evidence on environmental health conditions in the transitional phase—defined by the United Nations High Commissioner for Refugees as six months to two years after displacement. To address this gap in research, we conducted a systematic scoping review of environmental health conditions, exposures, and outcomes in transitional displacement settings, as well as reported obstacles and recommendations for improvement. Eighty-eight publications met the inclusion criteria. Water supply was the most frequently discussed environmental health topic. Overcrowding was the most common risk factor reported, Vibrio cholerae was the most common pathogen reported, and diarrhea was the most commonly reported health outcome. Obstacles and recommendations were categorized as institutional, political or implementation-based. Identified knowledge gaps included minimal information on setting logistics and on topics such as menstrual hygiene, oral hygiene and fomite contamination. In order to improve environmental health conditions in transitional displacement settings, all levels of government and non-governmental organizations should increase collaboration to improve resource provision. This study is the first to report on environmental health conditions in this important time of transition between the emergency and protracted stages of displacement.