| Custenau | |
| States: | Brazil |
| Region: | Mato Grosso |
| Extinct: | ? |
| Familycolor: | American |
| Fam2: | Southern ? |
| Fam3: | Paresí–Xingu |
| Fam4: | Waurá |
| Map2: | Lang Status 01-EX.svg |
| Iso3: | none |
| Linglist: | qbp |
| Glotto: | kust1238 |
| Glottorefname: | Kustenau |
Custenau (Kustenaú) is an extinct Arawakan language of Brazil.