It is widely recognised that photosynthesis in many important crops is well below its theoretical potential. With crop yields and stability under threat from the impact of climate change, there is now an urgent need to synthesise existing research on best practices for improving C3 photosynthesis in crops to optimise sustainable crop production and yields. Understanding and improving crop photosynthesis reviews the wealth of current research that addresses this challenge. This collection summarises our understanding of the general components of C3 photosynthesis, including its biophysics, biochemistry and genetics, as well as advances in techniques for improving photosynthesis, focussing primarily on light harvesting and optimising chloroplast function/light conversion.