| Settlement Type: | Town |
| Subdivision Type: | Country |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Pushpin Map: | Hungary |
| Pushpin Map Caption: | Location of Jánossomorja |
| Official Name: | Jánossomorja |
| Other Name: | Sanktjohann, Sanktpeter |
| Subdivision Type1: | County |
| Subdivision Name1: | Győr-Moson-Sopron |
| Subdivision Type2: | District |
| Subdivision Name2: | Mosonmagyaróvár |
| Area Total Km2: | 148.94 |
| Population Total: | 6283[1] |
| Population As Of: | 2019 |
| Population Density Km2: | auto |
| Postal Code Type: | Postal code |
| Postal Code: | 9241 |
| Area Code Type: | Area code |
| Area Code: | (+36) 96 |
| Coordinates: | 47.8°N 17.1167°W |
Jánossomorja is a town in Győr-Moson-Sopron County, Hungary. It is a connection between the two villages Szentpéter (German: Sanktpeter) and Szentjános (German: Sanktjohann), located close to the Austrian border. Before 1946, those were German settlements with the German names St. Johann (St. John) and St. Peter.