Chaim Hoffmann (later Yahil) was born in the town of Wallachisch Meseritsch in Moravia, then part of the Austro-Hungarian Empire (today: Valašské Meziříčí, in the Czech Republic).
He worked for the Zionist movement in Prague and published his first book (under the name Chajim Hoffmann), a history of the Zionist labor movement in Palestine (Träger der Verwirklichung: die zionistische Arbeiterschaft im Aufbau) in 1937/1938.
In 1949 Yahil returned to Israel joining the Jewish Agency Department of Absorption as director in Jerusalem.
In 1951 Yahil was appointed as head of Information Department in the Israeli Ministry of Foreign Affairs until 1953.
From 1965 until 1972 Yahil was Chairman of the Israeli Broadcasting Authority and until his death in 1974 was the leader of the "Whole land of Israel" movement.