Mixed production systems, in which producers have some combination of perennial and annual crops, livestock, and/or fisheries, are the most common form of farming in low- and medium-income countries, and they are increasingly of interest in high-income countries as an adaptive approach to climate change. Diversification in mixed systems can buffer against the risks climate change poses to food production systems through increased livelihood resilience, food security, and multiple ecosystem services. Mixed systems can provide near-term, local and regional resilience as well as contributing to sustained resilience in the global food system. Evidence and cases from mixed crop-livestock systems, agroforestry, and integrated aquatics systems demonstrate the technical, cultural, and socio-economic benefits, challenges and barriers to implementation. Support for mixed systems, including context-specific financial mechanisms, knowledge sharing, and markets, could help advance the adaptation and mitigation benefits of mixed systems. Failure to consider the place and context-specific dynamics in implementing these systems can lead to maladaptive outcomes.