<p>Northwest Europe experienced considerable increases in wheat yield until the mid-1990s, but progress has remained stagnant since then. Estimating the relative contributions of improved genetics, historical climate change and agronomic management to this yield plateau is required to understand the feasibility of yield increases in the future. Analysis of high-quality experimental data revealed yield gains due to improved genetics of 74–84 kg ha⁻¹ yr⁻¹ during the period 1994–2016. Thus far, yield gains due to historical climate change of 26–60 kg ha⁻¹ yr⁻¹ were estimated over the same period using a well-validated crop model across regions, soil types and cultivars. Given the absence of genetic and climatic yield ceilings, we conclude that agronomic management is responsible for the wheat yield plateau in northwest Europe, contributing to unrealized potential yield gains of 67–114 kg ha⁻¹ yr⁻¹. Breaking the yield plateau will require due attention to agronomic constraints at the farm level and continued monitoring of genetic gains and climate change impacts on wheat yields.</p>