Dhalgren, a science fiction novel by Samuel R. Delany

Dahlgren Hall at the U.S. Naval Academy in Annapolis, Maryland

The Dahlgren gun, a type of smoothbore cannon designed by the Admiral and used by the U.S. Navy

Dahlgren, Illinois

The Dahlgren system, created by Danish botanist Rolf M. T. Dahlgren (1932-1987)

The Dahlgren Affair, his failed mission to assassinate leaders of the Confederacy

Rear Admiral John A. Dahlgren (1809-1870), a U.S. Navy officer

Dahlgren, Virginia, and the U.S. Naval base there

Colonel Ulric Dahlgren (1842-1864), his son, a U.S. Army officer

Jay Dahlgren, a Canadian javelin thrower

Lake Dahlgren, a small lake located in Oklahoma