Many initiatives to address contemporary complex challenges require the crossing of sector, domain, and level boundaries, which policy entrepreneurs are believed to facilitate. This study aims to enhance our understanding of how, why, and with what effect such entrepreneurs operate to cross boundaries. As this requires an account of both entrepreneurial strategy and the surrounding policy environment, we embed entrepreneurship in the policy frameworks of multiple streams, advocacy coalitions, and punctuated equilibrium. We use qualitative methods to analyse policy development for climate-smart agriculture (CSA) in Kenya. CSA is a cross-cutting strategy to sustainably increase agricultural productivity, resilience, and food security while curtailing greenhouse gas emissions. Our results demonstrate that policy entrepreneurs target varying ideas, interests, and institutions across boundaries in order to establish cross-boundary linkages, but this requires additional resources including connections, funding, and time. Simultaneously, this process offers opportunities, for instance, regarding choice of audience and potential resources to tap. Cross-boundary entrepreneurial strategies include venue shopping to soften up communities; framing CSA in multiple ways to address different audiences; demonstrating brokerage between coalitions through impartial leadership and creating a neutral institutional setting; and process manipulation to bypass complexities arising from the scattered policy environment. Although entrepreneurs managed to realize the adoption of a Kenya CSA strategy, the process displays limited changes in policymakers’ ideas; the policy remains the main responsibility of the agriculture ministry alone and receives limited support from local authorities. This raises questions regarding the cross-boundary nature and implementability of this strategy.