Energy consumption and associated greenhouse gas (GHG) emissions will increase significantly in the developing world. Scaling up bioenergy use and reducing GHG emissions is vital to achieving the Nationally Determined Contributions and advance the greener economy. This study explored the life cycle inventories of Nigeria’s palm oil processors towards supporting technology advancement and renewable energy transition in the African oil palm industry. We compiled a gate-to-gate life cycle inventory of large-scale, semi-mechanized, and smallholder processors of oil palm fresh fruit bunch in Nigeria. The inventory includes materials and energy inputs to the system and outputs and emissions to the environment. The inputs are diesel, water, electricity, empty fruit bunch, palm kernel shell and mesocarp fibre for a functional unit of 1 tonne of fresh fruit bunch while the outputs include crude palm oil, palm kernel, and all emissions to air and soil. Carbon dioxide (CO2) and dinitrogen oxide (N2O) emissions were 47% and 73% more in the smallholder mills than in the large-scale mills, respectively. The semi-mechanized mills produced 73% more N2O than the large-scale mills. In contrast, large-scale mills emit 71% more methane (CH4) than smallholder and semi-mechanized mills. The study reveals critical hot spots of GHG emissions in Nigeria’s oil palm industry, including CO2, N2O, and CH4 from the smallholder, semi-mechanized, and large-scale processors, respectively. These findings will contribute to supporting policymaking, technology advancement, and promoting the use of bioenergy within and outside the industry as an essential strategy for mitigating climate change.