It is usually female (but occasionally also male).
The name derives from the Old Norse name (Dagmær), dagr meaning "day", and mær meaning "daughter", "mother" and "maiden" (or mari meaning "famous" and "powerful" in Old Saxon).
Outside of Scandinavia, Dagmar is also used in Austria, the Czech Republic, Estonia, Germany, the Netherlands, Poland (Dagmara), Slovakia and Switzerland.
In Greece (Δάμαρις) also, even though rarely; it is a Saint of the Orthodox church and it is said to be the first Christian woman of Athens, following the visit of Apostle Paul to Athens in 51 AD.
Nicknames of Dagmar are Dagie, Dagmarka, Dasha, Dáša, Digi, and Mara (in Czech); Dagi and Daggi (in German).