Background: International organisations and development agencies have important roles to play in addressing noncommunicable diseases (NCDs) and their risk factors at the nexus of health, socioeconomic, and environmental development challenges. Much of this work occurs through direct engagement with the private sector. We aimed to assess the types of private sector engagement (PSE) approaches and the degree of alignment across ten major international organisations whose work is critical to achieving global NCD and mental health goals. Methods: We examined the publicly available PSE strategy documents for a purposive sample of ten major international development partners. We obtained copies of each organisation’s publicly available PSE policy documents and extracted data on the stated purpose, processes, and types of engagement. We used thematic analysis and triangulation to identify areas of agreement, dissonance and silence across the policy approaches. Results: Whilst all PSE documents emphasised the importance of conducting due diligence, they varied widely in their approach to the risk of engagement and the sophistication of potential conflict of interest management strategies. Many documents were silent on prohibited industries, managing reputational risks, and guidance to Member States. The proactive engagement stance in USAID and World Bank policy documents contrasted starkly with more conservative approaches advanced by UNDP, FAO, and WHO. Conclusions: The core practices of conducting due diligence and risk mitigation are common to all of the major international organizations we assessed, however, the framing, content, and PSE processes vary widely. The potential impact of these findings is that WHO and other partners can focus on adopting common approaches wherever possible for greater coherence and smoother coordination across the wider development system.