Zadar IV was an inhabited planet with an ocean filled with dolphins and other marine life. It was the fourth planet in the Zadar planetary system. The planet was affiliated with the United Federation of Planets.

Prior to stardate 41509 , Starfleet oceanographer Lieutenant Harry Bernard, Sr. was stationed on Zadar IV with his son Harry Jr. They lived on the beach and Harry Jr. often saw dolphins playing in the ocean there. They were later the inspiration for his first attempt at sculpting. (TNG: "When The Bough Breaks")