Improving sheep system sustainability is of key importance to producers, processors, retailers and government, yet balancing interdependent and opposing environmental, economic and social factors is a Herculean task. Mixed farming systems provide an option for improving all three facets of sustainability, although negative trade-offs must be minimized. A variety of opportunities exist for integrating sheep grazing enterprises into other systems, including arable rotations, viniculture, silvopasture, cattle, goat and agrivoltaics. The principal benefit of mixed systems is to diversify outputs per unit of land. Although yields of individual products may sometimes be less than in single-output systems, this is outweighed by greater combined yields, and in many mixed systems, lamb performance remains equal to that of sheep-only systems. From an environmental perspective, integrating sheep into other systems may also confer benefits for nutrient cycling, resource use, soil health, carbon sequestration, greenhouse gas emissions, biodiversity and sheep health.