A price on carbon is driving land-use changes globally, including the establishment of biodiverse carbon plantings to sequester carbon. The biodiversity benefits of these plantings depend on many factors, including their spatial locations. We provide an approach for assessing the opportunities and spatial priorities for carbon sequestration and biodiversity restoration through biodiverse carbon plantings. Using Australia as a case study, we show how carbon market conditions affect the potential for achieving biodiversity benefits through restoring heavily cleared vegetation types to 30% of their original extent. Using a midrange carbon price, AU$20 per ton, we discovered that the top 25% of priority areas for biodiverse carbon plantings could sequester 132 megatons of carbon dioxide equivalents annually—more than 5% of Australia's emissions. Lower carbon prices limit biodiversity outcomes. Spatial priorities for sequestering carbon are different from those for restoring biodiversity; therefore, accounting for both factors maximizes efficiency and opportunities.