The Chesapeake Biological Laboratory (CBL) is a marine research facility of the University of Maryland Center for Environmental Science (UMCES). UMCES sister campuses include the Horn Point Laboratory, Cambridge, on Maryland's Eastern Shore, and the Appalachian Laboratory, Frostburg, in the mountains of Western Maryland. UMCES research fleet is located on the CBL Campus.

CBL was founded in 1925 by Dr. Reginald V. Truitt, and is located on the Western Shore of the Chesapeake Bay, 60 miles SSE of Washington, D.C. A mid-Bay location at the mouth of the Patuxent River places it within easy reach of the diverse aquatic and terrestrial habitats of one of the world's largest estuarine ecosystems. CBL is a charter member of the National Association of Marine Laboratories.