In Morocco, covering the head with a scarf is not mandatory. You will see women with head scarves and women without. Niqabs are scarce and burqas are prohibited by the State. That said, traveling with a scarf is a good idea.
Should I cover my hair in Marrakesh?
Whatever you wear in Marrakech, never excessively reveal the body outside of the riad or hotel where you are staying. Cover décolletage, shoulders and thighs. It's not necessary for non-Muslim women to wear a hijab (a type of scarf covering the hair).