Delaware shares its borders with exactly three states. Each border has unique features that shape Delaware’s geography and connections. For example, Pennsylvania’s border with Delaware is famous for its unusual circular shape called the Twelve-Mile Circle. Meanwhile, Maryland surrounds Delaware on its western and southern sides, and New Jersey lies across the Delaware River and Bay to the east.
Below is a detailed look at each state that borders Delaware.
State Name This column lists the name of the neighboring state.
Capital City This shows the capital city of each bordering state.
Population (2023 est.) This gives the estimated number of people living in each state as of 2023.
Border Length (km) This indicates the length in kilometers of the border Delaware shares with each state.
states that border delaware
| State Name | Capital City | Population (2023 est.) | Border Length (km) |
|---|---|---|---|
| Maryland | Annapolis | 6,180,253 | 158 |
| Pennsylvania | Harrisburg | 12,961,677 | 40 |
| New Jersey | Trenton | 9,271,689 | 185 |
Descriptions
Maryland
Maryland shares the entire western and southern land border with Delaware on the Delmarva Peninsula. It’s known for its Chesapeake Bay blue crabs, historic Annapolis, and being a key neighbor in the Mid-Atlantic region.
Pennsylvania
Pennsylvania borders Delaware to the north along a unique circular boundary known as the Twelve-Mile Circle. As one of the original thirteen colonies, it shares a deep history with Delaware, with Philadelphia being a major nearby metropolitan hub.
New Jersey
New Jersey shares a significant water border with Delaware along the Delaware River and Bay. Residents often cross between the two states via the Delaware Memorial Bridge or the Cape May-Lewes Ferry, connecting the famous Jersey Shore with Delaware’s beaches.
