Significance The synergistic impacts of rapid climatic warming and fisheries harvest are threatening the sustainability of wild fisheries. Their collective impact on fish recruitment—a key process underpinning stock abundance—remains poorly understood. We experimentally exposed fish populations to realistic warming and fishing-selection regimes over multiple generations and found that warmed populations experienced a severe decline in recruitment rate. This warming-induced decline was exacerbated by size-selective fishery harvest. Once warming and size-selective fishing were relaxed, recruitment rates rapidly recovered. Our results suggest that synergistic impacts of fishing and warming can have delayed effects on stock resilience and that preserving fish body size diversity will help to increase their resilience to global warming.