Healers are various people in he Zelda series that have the ability to easily heal people of all races.
The Legend of Zelda: A Link To The PastEdit
Healers can be found across the land, known as the Potion Sellers. These could possibly be considered Healers.
The Legend of Zelda: Ocarina of TimeEdit
The main healer here is the Old Hag in Kakariko Village. She appears to have the great knowledge of healing and poition-brewing, and thus is considered a healer.
The Legend of Zelda: Twilight PrincessEdit
Renado is a healer. He can reportedly heal anyone of any race and apparently does so often.