Human ascariasis, caused by soil-transmitted nematode Ascaris, is one of the most important and commonest neglected tropical diseases. Approximately 0.8 billion people are affected with this worm worldwide, equating to 0.86 million disability-adjusted life-years (DALYs). Lipids are of vital importance in biology of parasitic worms, particularly in relation to cellular membranes, energy storage, and intra- and intercellular signalling. However, very little is known about the biology of lipids in parasitic nematodes. Using a high-throughput LC-MS/MS approach, we characterised the first global lipidome for Ascaris. Totally, we confidently identified and quantified (i.e. in precise molar amounts in relation to the dry weigh of worm material) nearly 600 lipid species across 18 lipid classes in five key developmental stages/sexes and three organ systems of adult male and female Ascaris. The results showed substantial differences in the composition and abundance of lipids with key roles in cellular processes and functions (e.g. energy storage regulation and membrane structure) among distinct stages and among organ systems, likely reflecting differing demands for lipids, depending on stage of growth and development as well as the need to adapt to constantly changing environments within and outside of the host animal. This work provides the first step toward understanding the biology of lipids in Ascaris, with possibilities to work toward designing new interventions against ascariasis.