| Newtowne Neck State Park | |
| Photo Alt: | Landscape |
| Photo Width: | 280 |
| Map: | USA Maryland |
| Map Width: | 280 |
| Relief: | 1 |
| Label: | Newtowne Neck State Park |
| Location: | St. Mary's County, Maryland, United States |
| Nearest City: | Leonardtown, Maryland |
| Coordinates: | 38.2453°N -76.7081°W |
| Area: | 794acres |
| Elevation: | 13feet |
| Established: | 2009 |
| Designation: | Maryland state park |
| Administrator: | Maryland Department of Natural Resources |
Newtowne Neck State Park is a public recreation area located 4miles southwest of Leonardtown in St. Mary's County, Maryland. The state park sits on a peninsula that is surrounded by Breton Bay, St. Clements Bay, and the Potomac River. It is managed by the Maryland Department of Natural Resources.
The park was part of the state's purchase of former Jesuit holdings in Southern Maryland in 2009. The discovery of military ordnance on the site forced the park to close in 2012. It reopened to the public in 2014.
The state park offers 7miles of undeveloped shoreline, fishing, hunting, unimproved hiking and biking trails, and kayaking.