Largest Lakes in Ohio
7 Ohio lakes with measured surface area, ranked by acreage. The biggest lake in Ohio is Caesar Creek Lake, which tops the list at 2,830 acres in Warren County.
Reading Ohio's size profile
Ohio's largest lake by surface area is Caesar Creek Lake in Warren County, spanning 2,830 acres. Most of Ohio's biggest waters are reservoirs — dammed river valleys built for water supply, flood control, and recreation, so their footprints shift with pool level.
Surface area is a poor proxy for water quality on its own — a large lake can hold a clean, deep core and a nutrient-loaded bay at the same time. Each lake below links to its full report card with grade, clarity, depth, and EPA impairment status. Area figures come from state DNR surveys and the USACE National Inventory of Dams; grades come from EPA and state monitoring data.
The 7 biggest lakes in Ohio by surface area
| # | Lake | County | Surface area | Max depth | Grade |
|---|---|---|---|---|---|
| 1 | Caesar Creek Lake | Warren | 2,830 acres | - | D |
| 2 | Pleasant Hill Reservoir | Richland | 2,600 acres | - | F |
| 3 | Tappan Lake | Harrison | 2,350 acres | - | F |
| 4 | Charles Mill Reservoir | Ashland | 1,350 acres | - | F |
| 5 | Clear Fork Reservoir | Morrow | 1,024 acres | - | F |
| 6 | Leesville Lake | Carroll | 1,000 acres | - | D |
| 7 | Lake Vesuvius | Lawrence | 143 acres | - | C |
Frequently Asked Questions
What is the largest lake in Ohio?
The largest lake in Ohio in the LakeGrade dataset is Caesar Creek Lake in Warren County at 2,830 acres. Water quality grade: D.
How is lake surface area measured?
Surface area comes from state DNR lake surveys and, for reservoirs, US Army Corps of Engineers (USACE) National Inventory of Dams records. Area is reported in acres at normal pool level. Reservoirs rise and fall with management and drought, so their listed area is the long-term normal rather than a single-day reading.
Are Ohio's largest lakes natural or reservoirs?
Of the top 7 Ohio lakes by area, 7 sit on a dammed river (reservoirs) and 0 are natural basins. Glacial states (MN, WI, MI, NY) skew natural; plains and southern states (MO, IA, ND, OH) skew toward reservoirs built for water supply, flood control, and recreation.
Do larger lakes have better water quality?
Not reliably. Quality varies more within a big lake than between lakes — a large lake can have a clean, deep main basin and a murky, algae-prone bay fed by a tributary, so one grade can mask wide swings. Depth, watershed land use, and how fast the lake flushes matter far more than raw surface area.
How big is the typical Ohio lake in this ranking?
Across the top 7 Ohio lakes by surface area, the median is 1,350 acres (Charles Mill Reservoir). This list is biased toward the biggest waters; the typical Ohio lake is far smaller.
Where to stay near Ohio's largest lakes
Planning a trip? Jump to live cabin, resort, and hotel availability near Ohio's biggest lakes.
- Caesar Creek Lake · Warren CountyCabins & hotels near Caesar Creek Lake →
- Pleasant Hill Reservoir · Richland CountyCabins & hotels near Pleasant Hill Reservoir →
- Tappan Lake · Harrison CountyCabins & hotels near Tappan Lake →
- Charles Mill Reservoir · Ashland CountyCabins & hotels near Charles Mill Reservoir →
- Clear Fork Reservoir · Morrow CountyCabins & hotels near Clear Fork Reservoir →