Dagmar may refer to:
- Dagmar (given name), a feminine Scandinavian and German given name.
- Dagmar of Denmark (disambiguation), multiple royal women.
- Dagmar, the better-known stage name -- the other being Jennie Lewis -- of American actress Virginia Ruth Egnor.
- Dagmar bumpers, slang term for the artillery-shell-shaped styling elements found on the front bumper/grille assemblies on several makes of cars produced in the 1950s (named for Egnor after her rise to fame)
- Dagmar's Twin 40s, also named for Egnor, was the nickname for the twin 40-mm anti-aircraft guns mounted on the Korean War-era M19 Gun Motor Carriage
- 1669 Dagmar (1934 RS), a main-belt asteroid
- Dagmar (automobile), sports version of the Crawford automobile
- DAGMAR marketing, an advertising model