The Curve-billed Reedhaunter (Limnornis curvirostris) is a species of bird in the Furnariidae family. It is found marshy areas of north-eastern Argentina, south-eastern Brazil, and Uruguay. It occupies a similar ecological niche to some reed warblers.

The Curve-billed Reedhaunter is monotypic within the genus Limnornis. The superficially similar Straight-billed Reedhaunter is sometimes also included in Limnornis, but evidence suggests it is closer to Cranioleuca spinetails than it is to the Curve-billed Reedhaunter. Additionally, the name Limnornis was also mistakenly given to fossils from Romania, but these remains have since been reclassified as Eurolimnornis and Palaeocursornis