The agri-food sector is globally critical for tackling climate change and environmental decline, poverty and inequity, and hunger and nutrition. Achieving the Sustainable Development Goals (SDGs) will require huge increases in investment in agrifood research and innovation (ARI) (Herrero et al., 2020). Innovation is needed in policy, social institutions, finance, technology, and management practices.This Research Topic (RT) was initiated by an international Commission on Sustainable Agriculture Intensification, CoSAI (CoSAI Secretariat, 2022), created to promote more and better innovation to support rapid sustainable and equitable transformation of agrifood systems in the Global South. This Research Topic covers three main areas that are key to decision making by research/innovation organizations and their funders (Figure 1): ARI gaps, needs and priorities; pathways, approaches and instruments; and assessment of ARI with a sustainability lens. It brings together eight articles generated from CoSAI working papers with four from an open call. The articles are rich and the findings are often surprising. Space only allows a few points: we urge readers to consult the full articles.. ARI investment gaps, needs and priorities . . Current investment in ARI must be reoriented to transform agrifood systems Rosegrant et al. estimate the ARI investment gap for the Global South at around US$10.5 billion per year, and provide a useful comparison with related estimates from other models. Prasad et al. summarize an ambitious first attempt to estimate current investment in ARI for the Global South, including broader investments in innovation as well as R&D.