1. Eastern European, female variant of the Biblical name Dan [OT Genesis 30:6], meaning "he judged" in Hebrew and a variant of Daniella.
There are many pet names for Dana and/or Daniela in Czech, including Danka, Danuše, Danuška, Danička, Danula, Danulka.

2. In Polish Dana is also a diminutive of Bogdana, from old Slavonic "gift of God" and a pet name for Daria.

3. In the US Dana is derived from the surname, which is of uncertain origin, and may be male or female.