Highways

The three state highways, MD-4, MD-5, and MD-235, run throughout the County are the gateway to much of the east coast hubs via U.S. 301, I-95, and the Washington D.C. Beltway, or I-495.

Daily bus service to the Washington D.C. and particular major employers is available from the County as well.

Air

The County boasts access to three major airports:

• St. Mary's County Regional Airport (2W6)
  • The St. Mary's County Regional Airport is at the heart of the County's aviation industry. The County-owned local airport is available for private and charter air travel. Fuel sales, maintenance, flight instruction, and aircraft rental are offered at the airport.
• Ronald Reagan Washington National Airport (DCA)
  • Located in Arlington, Virginia, Reagan National is less than an hour and a half from St. Mary's County's business districts. As the main airport serving the nation's capital, DCA offers multiple flights per day to cities across the country. The airport also supports operations, cargo, and general aviation activities. DCA is directly on Washington, D.C.'s Metro transit system.
• Washington Dulles International Airport (DIA)
  • Dulles ([dull-is]) is less than two hours from St. Mary's County's business districts and is one of two major international airports in the Washington, D.C. region. The airport supports cargo, general aviation, aviation operations, and commercial flights nationally and internationally. Dulles is part of DC's Metro transit system expansion.
• Baltimore/Washington International Thurgood Marshall Airport (BWI)
  • BWI is less than hours away from St. Mary's County's business districts, just outside Baltimore, and only 30 miles from Washington, D.C. The airport supports both national and international travel and has over 400,000 square feet of cargo space.

Ports

The Port of Baltimore, a leading U.S. automobile and break-bulk port with seven public terminals including a state-of-the-art Intermodal Container Transfer Facility, is 81 miles from Leonardtown.

The County has the most shoreline in Maryland, meaning St. Mary's has abundant water access for private vessels, kayaks, and more.

Rail

St. Mary's County's closest rail connects are in Waldorf, Maryland, about 45 minutes from Lexington Park, Maryland. There, companies can access the CSX Transportation Rail Depot.

Also, individuals are able to drive to the Branch Avenue Metro Station on the DC Metro's Green Line to avoid driving (and parking) in Washington, D.C.