Maryland Route 273 (MD 273) is a state highway in the U.S. state of Maryland. Known for most of its length as Telegraph Road, the state highway runs from U.S. Route 1 (US 1) near Harrisville east to the Delaware state line near Appleton, where the highway continues east as Delaware Route 273 (DE 273). MD 273 is the main east–west highway of northern Cecil County, connecting Conowingo (via US 1), Port Deposit (via MD 276), and Rising Sun with Newark, Delaware, via the communities of Calvert and Fair Hill, where the highway intersects MD 272 and MD 213, respectively. The state highway also provides access to Fair Hill Training Center. MD 273 contains a section of MD 274 Truck between MD 274 in Rising Sun and MD 272 in Calvert.