Payaguá (Payawá) is an extinct language of Paraguay, Argentina, and Bolivia, spoken by the Payaguá. It is usually classified as one of the Guaicuruan languages, but the data is insufficient to demonstrate that.
Viegas Barros (2004) proposed that Payagua may be a Macro-Guaicurúan language. However, Campbell (2012) classifies Payagua as a language isolate.
An automated computational analysis (ASJP 4) by Müller et al. (2013) found lexical similarities between Payagua and the Chonan languages. However, since the analysis was automatically generated, the grouping could be either due to mutual lexical borrowing, genetic inheritance, or chance resemblances.