| Šumera | |
| Source1 Location: | Dargužiai village surroundings |
| Mouth Coordinates: | 55.2851°N 24.1886°W |
| Subdivision Type1: | Country |
| Subdivision Type2: | Region |
| Length: | 26.2km (16.3miles) |
| Discharge1 Avg: | 0.45 m³/s |
| Basin Size: | 89km2 |
| Tributaries Left: | Juodupis, Ringa |
The Šumera is a river in the Kėdainiai district municipality, Kaunas County, central Lithuania. It flows for and has a basin area of 89km2. The river flows into the Obelis (from the right side), a tributary of the Nevėžis, which is in turn a tributary of the Neman.
The Šumera starts nearby former Dargužiai village and flows mostly southwards through agriculture lands and the Lančiūnava-Šventybrastis Forest. It meets the Obelis in Pašumerys village.
The name Šumera (or Šiumera) is of obscure origin, maybe derived from Lithuanian Germanism šiumas ('foam, decoction').