Dagr is the personification of day in Norse mythology.
Dagr may also refer to:
- Defense Advanced GPS Receiver, a handheld device
- Direct Attack Guided Rocket, a weapons system
- "Dagr", a song by Wardruna from the 2009 album Runaljod – Gap Var Ginnunga
- Dragon Alliance of Gamers and Role-Players, the group that founded Dragon Con