Yitzhak Tunik was born in Russia in 1911 and came on Aliyah to Mandatory Palestine in 1934. He studied law in the School of Law set up by the British Mandatory Government and in 1945 founded a private law firm in Jerusalem. In 1948, a short while after the declaration of the founding of the State, he was drafted into the IDF and from 1949 until the end of his military service, he served as the chief military prosecutor. After his release from the army, Yitzhak Tunik was a partner in the law firm established by Aharon Hoter-Yishai, his former army commander.
In 1972 he was elected president of the Israel Bar Association.
In 1975 he was again elected president of the Israel Bar Association—which position he held until 1979.
In January 1982, Yitzhak Tunik was appointed State Comptroller and Ombudsman by the State President and he served in this position from January 14th, 1982 through to January 7th, 1987.
In his position as State Comptroller, he was one of the drafters of the Basic Law: State Comptroller and a member of the group that initiated the establishment of the Beisky Commission – the national commission of inquiry into the bank shares regulation crisis.
He served as the head of the Israel Association of Alumni of Hebrew University.
Yitzhak Tunik died on the 9th of Jaunary 1989.