Fraxinus caroliniana, the pop ash, Florida ash, swamp ash, Carolina ash, or water ash, is a species of ash tree native to fhe Southeastern United States from southern Virginia to Texas. It was originally described by the botanist Philip Miller. It is a small tree about 40 ft (12 m) tall. It has compound leaves, with ovate, coarsely serrated leaflets 3–6 in (7.6–15.2 cm) long and 2–3 in (5.1–7.6 cm) wide arranged oppositely. The fruit is frequently a 3-winged samara with a flat seed portion, and a bright violet color. It is the smallest of eastern North American ash species. The wood is light and fairly soft. It is typically found in coastal swamps and subtropical lowlands. Fraxinus caroliniana is dioecious, with male and female flowers produced on separate individuals.

The tree is threatened by the emerald ash borer, an invasive species of beetle.