Global agricultural development programs aim to support smallholder farmers and farming communities by strengthening sustainable and resilient food production systems – which can also promote climate change mitigation as a co-benefit by reducing the emissions and enhancing removals of greenhouse gases (GHG). This study presents estimated GHG emissions reductions of almost 100 agricultural development projects over 51 low- and middle-income countries supported by the International Fund for Agriculture Development (IFAD), USAID-Feed the Future (FTF) Initiative, and Foreign, Commonwealth and Development Office (FCDO, previously DfID). Together, these projects promoted a net GHG emissions reduction of 6.5 MtCO2e per year. The forest management and promotion of improved agroforestry systems in the project areas contributed the most to the total mitigation co-benefits of the investment portfolios (∼3.9 MtCO2e/y). Improved crop management with minimum tillage practices, residue incorporation, water management in paddy rice, and the use of organic fertilizers also made a large contribution to the GHG emissions reduction (∼1.5 MtCO2e/y). Grass and pasture land management across the selected projects account for a net emission reduction of 0.2 MtCO2e/y. The implementation of improved agricultural practices in combination proves more effective for improving productivity and generating mitigation co-benefits than used in isolation. However, the aggregate impacts of soil organic carbon (SOC) sequestration should be interpreted carefully, which quickly can be lost quick. The interventions promoted by the global agricultural development programs have shown immense potential in reducing net GHG emissions or emission intensity in agriculture and allied sectors. For moving forward to achieve the net-zero and 1.5 °C goals including food security, the global agriculture development programs need to prioritize working on agriculture policy development and implementation so that agriculture expansion does not continue to drive land-use change. This needs to move from the traditional agriculture development programs to transformational changes.