See also: Guilford Lake (Ohio).
| Official Name: | Guilford Lake, Ohio |
| Settlement Type: | Census-designated place |
| Mapsize: | 300px |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Ohio |
| Subdivision Type2: | County |
| Subdivision Name2: | Columbiana |
| Subdivision Type3: | Township |
| Subdivision Name3: | Hanover |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 7.51 |
| Area Land Km2: | 6.13 |
| Area Water Km2: | 1.38 |
| Area Total Sq Mi: | 2.90 |
| Area Land Sq Mi: | 2.37 |
| Area Water Sq Mi: | 0.53 |
| Population As Of: | 2020 |
| Population Total: | 1188 |
| Population Density Km2: | 193.81 |
| Population Density Sq Mi: | 501.90 |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation Ft: | 1132 |
| Coordinates: | 40.8033°N -80.8772°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 44423, 44432 |
| Area Code: | 330, 234 |
| Blank Name: | FIPS code |
| Blank Info: | 39-32680 |
| Blank1 Name: | GNIS Feature ID |
| Blank1 Info: | 2805292 |
| Blank2 Name: | School District |
| Blank2 Info: | United Local School District |
Guilford Lake is an unincorporated community and census-designated place in northeastern Hanover Township, Columbiana County, Ohio, United States. It surrounds the eponymous Guilford Lake reservoir.[2] The population was 1,188 at the 2020 census.[3]
Guilford Lake was constructed as a canal feeder reservoir for the Sandy and Beaver Canal in 1834. It took its name from Edward H. Gill, chief engineer of the canal company.[4] When the canal era ended, local farmers breached the dam, drained the lake, and used the fertile lake bottom for farm land. In 1932, a new dam was completed and the land surrounding it was designated a state park in 1949.[5] The community was first listed as a CDP for the 2020 census.