| En Name: | Suslonger |
| Ru Name: | Суслонгер |
| Loc Name1: | Сӱзлэҥер |
| Loc Lang1: | Meadow Mari |
| Loc Lang2: | Hill Mari |
| Coordinates: | 56.3°N 63°W |
| Map Label Position: | top |
| Federal Subject: | Mari El Republic |
| Adm District Jur: | Zvenigovsky District |
| Adm Selsoviet Jur: | Suslonger Urban-Type Settlement |
| Adm Selsoviet Type: | Urban-type settlement |
| Adm Ctr Of: | Suslonger Urban-Type Settlement |
| Inhabloc Cat: | Urban-type settlement |
| Mun District Jur: | Zvenigovsky Municipal District |
| Urban Settlement Jur: | Suslonger Urban Settlement |
| Mun Admctr Of: | Suslonger Urban Settlement |
| Pop 2010Census: | 3161 |
| Current Cat Date: | 1942 |
| Postal Codes: | 425050 |
| Suslonger population | |
| Label1: | 2010 Census |
| Data1: | 3,161 |
| Label2: | 2002 Census |
| Data2: | 3,642 |
| Label3: | 1989 Census |
| Data3: | 4,137 |
| Label4: | 1979 Census |
| Data4: | 3,655 |
Suslonger (Russian: Сусло́нгер; Сӱзлэҥер, Süzleŋer) is an urban locality (an urban-type settlement) in Zvenigovsky District of the Mari El Republic, Russia. As of the 2010 Census, its population was 3,161.
Urban-type settlement status was granted to it in 1942.
Within the framework of administrative divisions, the urban-type settlement of Suslonger, together with one rural locality (the settlement of Mochalishche), is incorporated within Zvenigovsky District as Suslonger Urban-Type Settlement[1] (an administrative division of the district).[2] As a municipal division, Suslonger Urban-Type Settlement is incorporated within Zvenigovsky Municipal District as Suslonger Urban Settlement.[3]