| Official Name: | Waterloo, Missouri |
| Pushpin Map: | Missouri |
| Pushpin Label: | Waterloo |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Missouri |
| Subdivision Type2: | County |
| Subdivision Name2: | Clark |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Ft: | 554 |
| Coordinates: | 40.4494°N -91.6689°W |
| Area Code: | 660 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 755469 |
Waterloo is a community in Clark County, Missouri, United States. The community is located on a sharp meander in the Fox River. Nearby towns include Kahoka (3 miles southwest), Revere (2.5 miles north) and Wayland (6 miles southeast).[1]
A post office called Waterloo was established in 1837, and remained in operation until 1876.[2] Waterloo held the first county seat.[3]