The name Acrocephalus refers to the peaked crown found on reed warblers in this genus and can be translated to mean "topmost head" in Greek.

[4] Within subfamily Acrocephalinae, the Australian reed warbler is recognised as belonging to a monophyletic group consisting of Palearctic and Australasian region species.

[5] However, recent mitochondrial DNA analysis infers that pacific reed warblers (Acrocephalus spp.)

[6] There are two recognised subspecies: This species appears long (15–18 cm), slender and plain, with drab brown plumage that varies with wear.

[2][8] An indistinct pale brown supercilium extends from close to the bill to midway on the ear-coverts, the feathers on the crown are slightly elongated and they are often raised to form a crest during song.

[10] Australian reed warblers are found in a wide range of natural and man-made wetlands including fresh, brackish and saltwater environments.

[2][9] This species forages mainly individually but sometimes in pairs, in dense vegetation on insects and spiders[7] and occasionally molluscs and seeds.

[2][7] Unlike all other Acrocephalus species which are sedentary, the Australian reed warbler migrates seasonally.

[11] Males use song extensively throughout the breeding season and can be observed singing from a perched position on breeding ground reeds with their fore crown feathers raised and throat feathers puffed out whilst singing.

[10] These nest-like structures lack the strength and shape to be suitable for eggs and chicks, and are constructed prior to breeding commencement.