* Pelirrojo/a: This is the most common and direct translation. *Pelirrojo* is masculine, and *pelirroja* is feminine. So you would say "Es pelirrojo" (He is ginger-haired) or "Es pelirroja" (She is ginger-haired).
* Pelo rojo: This literally means "red hair". While it works, *pelirrojo/a* is more specific to the color we typically associate with ginger hair, especially if the hair is more orange than red.
* Rojo/a de pelo: This is less common, but also means "red-haired".
In some regions, you might also hear:
* Colorado/a: In some Latin American countries, "colorado" can refer to red hair, though it can also just mean "red" in general.
In summary, the best and most common translation is *pelirrojo/a*.