Background An estimated two billion people globally suffer from undernutrition, and yet, despite consensus that improving nutrition is one of the best investments for promoting health and alleviating poverty, nutrition remains chronically underfunded and under-prioritized. Successfully scaling global efforts to address undernutrition requires an understanding of the landscape of potential donors and partners that can be mobilized toward improving nutrition globally. Objective To conduct independent reviews of the European and US landscapes of donors and partners focused on undernutrition, and identify opportunities to leverage outreach and advocacy efforts toward increased engagement and funding for nutrition. Methods We present the primary findings from two independent landscaping studies conducted between September 2010 and March 2011. Research methods included desk-based research and interviews with stakeholders in bilateral and multilateral organizations ( n = 19), private industries ( n = 46), private funders ( n = 16), and civil society organizations ( n = 29). We report the key thematic findings by sector and the challenges and opportunities for increased engagement and funding for nutrition. Results Nutrition is a growing priority for a number of stakeholders across sectors. Strategic commitment to nutrition is emerging across multilateral and bilateral donor agencies; the private sector is increasingly interested in engaging in addressing undernutrition; and nongovernmental and civil society groups are engaged in nutrition advocacy. Key opportunities to increase funding and partnership across sectors include leveraging bilateral and multilateral investments for nutrition across development priorities while ensuring sound commitments within donor policies, focusing on engaging the private sector across the food value chain, mobilizing new resources from private funders through effective communication and outreach, and continuing to prioritize ongoing impact assessment across a range of interventions. Conclusions Understanding the current European and US landscape of nutrition stakeholders helps to inform efforts to scale the type of investments and partnership needed to make effective impacts on undernutrition globally. Turning the existing opportunities into results will require effective coordination, strong communication, and active participation across sectors.