The United Nations (UN) 2030 Agenda, borne from the most inclusive policy dialogue ever, emphasized partnerships built upon collaboration to achieve sustainable goals, as documented in SDG17. However, the building and construction sector has been experiencing sustainability issues, leading to several traditional government-led initiatives in the built environment. The private sector is critical to achieving the sustainable development goals (SDGs) and the 2030 Agenda by interacting with societies, governments, and other actors for a circular built environment. The circular economy (CE) is a paradigm that is becoming increasingly popular to drive the movement to sustainability, requiring the partnership of the private sector to be implemented successfully. However, the application of CE initiatives in the private sector engagement has received less attention. Recognizing the interaction of multiple parties’ influence on the uptake of a CE, this study thus seeks to examine the participation of the private sector in the CE in the built environment using a mixed review approach (scientometric and content analysis). The findings reveal that the private sector faces barriers in terms of financial and economic, institutional and technological, and political and regulatory factors. This research also identified areas for greater private sector involvement in CE initiatives in the built environment, such as resource reduction, sharing, and the adaptive reuse of existing buildings.