Crocothemis sanguinolenta is a species of dragonfly in the family Libellulidae. It is found in Angola, Botswana, Cameroon, Central African Republic, Chad, the Democratic Republic of the Congo, Ivory Coast, Egypt, Ethiopia, Ghana, Guinea, Kenya, Liberia, Madagascar, Malawi, Mali, Mozambique, Namibia, Nigeria, São Tomé and Príncipe, Sierra Leone, Somalia, South Africa, Sudan, Tanzania, Togo, Uganda, Zambia, Zimbabwe, and possibly Burundi. Its natural habitats are subtropical or tropical dry forests, subtropical or tropical moist lowland forests, subtropical or tropical dry shrubland, subtropical or tropical moist shrubland, rivers, intermittent rivers, shrub-dominated wetlands, freshwater marshes, and intermittent freshwater marshes.
Common names for this species include little scarlet, slim scarlet-darter and small scarlet.
Over most of its range, Crocothemis sanguinolenta is easily confused with Crocothemis erythraea, but C. sanguinolenta has a narrower abdomen (3 mm or less wide), the lateral carinae of S3 to S7 are usually marked with black dashes, and the pterostigmata are short and usually the same colour as the abdomen (red in mature males). The abdomen of Crocothemis erythraea is 3.5 mm or more wide, the lateral carinae of S3 to S7 are generally unmarked, and the pterostigmata are longer and less brightly coloured than the abdomen.