| Official Name: | Lake Lakengren, Ohio |
| Settlement Type: | Census-designated place |
| Pushpin Map: | Ohio |
| Pushpin Label: | Lake Lakengren |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Ohio |
| Subdivision Type2: | County |
| Subdivision Name2: | Preble |
| Subdivision Type3: | Township |
| Subdivision Name3: | Gasper |
| Unit Pref: | Imperial |
| Population As Of: | 2020 |
| Population Total: | 3,387 |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation M: | 332 |
| Elevation Ft: | 1089 |
| Coordinates: | 39.6883°N -84.6936°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 45320 |
| Area Code: | 937, 326 |
| Blank Name: | FIPS code |
| Blank Info: | 39135 |
| Blank1 Name: | GNIS Feature ID |
| Blank1 Info: | 2633187 |
Lake Lakengren (lock-n-grin, a Viking name meaning “Lake of the emerald green hills”)[1] is an unincorporated community and census-designated place in Gasper Township, Preble County, Ohio, United States. The population was 3,387 at the 2020 census.[2] A private planned community located southwest of Eaton, the northern portion of Lake Lakengren is served by Eaton Community Schools and the southern portion is served by the Preble Shawnee Local School District.
Lake Lakengren had its start in the late 1960s as a planned community.