State Park · Ohio
Grand Lake St. Marys State Park
- Location
- Mercer County, Ohio
- Nearest town
- 3.9 miles east of Celina
- Type
- State Park
About Grand Lake St. Marys State Park
Grand Lake spans 13,500 acres and is the largest inland lake in Ohio by surface area, though it stays shallow throughout, averaging only 5 to 7 feet deep. Park facilities are spread around the shoreline, mixed in with private property and a site run by Wright State University. Visitors come for boating, fishing, swimming and hunting, available across the property year-round.
Hours, fees, camping, reservations and closures are set by the park and change often. Check the official park site before you go.
Getting there
Grand Lake St. Marys State Park is in Mercer County, Ohio, 3.9 miles east of Celina. The Directions button takes you to the park's mapped location; the entrance may be elsewhere, so check the official site for the address to use.
State parks near Grand Lake St. Marys State Park
Within 60 miles, closest first, straight-line. All 78 in Ohio →
Lake Loramie State ParkState Park · Shelby County, OH14 miSE- Indian Lake State ParkState Park · Logan County, OH33 miE
Ouabache State ParkState Park · Wells County, IN35 miW- Kiser Lake State ParkState Park · Champaign County, OH37 miSE
Siegenthaler-Kaestner Esker State Nature PreserveState Natural Area · Champaign County, OH40 miSE
Sycamore State ParkState Park · Montgomery County, OH51 miS
Independence Dam State ParkState Park · Defiance County, OH54 miN
Summit Lake State ParkState Park · Henry County, IN55 miSW
Buck Creek State ParkState Park · Clark County, OH57 miSE
Towns near Grand Lake St. Marys State Park
State parks near Celina, State parks near Van Wert, State parks near Sidney, State parks near Lima, State parks near Greenville, State parks near Troy
Facts from Wikidata, checked September 25, 2026. Distances are straight-line.