The Cinnamon Bittern or Chestnut Bittern (Ixobrychus cinnamomeus) is a small bittern. It is of Old World origins, breeding in tropical Asia from Pakistan to Sri Lanka east to China and Indonesia. It is mainly resident, but some northern birds migrate short distances.

This is a small species at 38cm length, with a short neck and longish bill. The male is uniformly cinnamon above and buff below. The female's back and crown are brown, and the juvenile is like the female but heavily streaked brown below.

When surprised on its nest or concerned, it assumes the characteristic attitude of bitterns, aptly termed the On-Guard. The neck is stretched perpendicularly, bill pointing skyward, while the bird freezes, becoming astonishingly obliterated amongst its reedy environment.

Their breeding habitat is reedbeds. They nest on platforms of reeds in shrubs. 4-6 eggs are laid. They can be difficult to see, given their skulking lifestyle and reedbed habitat, but tend to emerge at dusk, when they can be seen creeping almost cat-like in search of frogs.

Cinnamon Bitterns feed on insects, fish and amphibians.