Born in Orsha, Russian Empire in 1894, Hoz immigrated to Ottoman Palestine along with his family in 1906. Beginning in 1909, he was part of the group that organized guarding activity of the city of Tel-Aviv. The group included Shaul Meiruv-Avigor, Eliyahu Golomb and Moshe Sharett. During World War I, Hoz volunteered for service in the Turkish army and was sentenced to death for continuing activities to secure the Jewish settlement of Palestine. He escaped death by fleeing to the south of Palestine which had just been conquered by the British.
Hoz was one of the organizers of the Jewish Legion. From 1920–1930, he was a member of the central Haganah committee. From 1931–1940, he was a member of the national Haganah command center. He went on to become one of the heads of the labor movement and a founding member of the socialist Ahdut HaAvoda party. In 1935 he was appointed vice-mayor of Tel-Aviv, and later head of the state department of the Histadrut (Labor Federation).
Hoz died in a car accident in December 1940 on his way to an Aviron board meeting. In his car were his wife Rivka (sister of Moshe Shertok later to be known as Moshe Sharett, making Sharett Dov's brother-in-law), daughter Tirza, sister in law Tzvia Sharett and business partner Yitzhak Ben Yaacov.
Hoz was the founder and CEO of "Aviron," a pioneer of aviation in Israel that trained pilot and established flight lines in Israel and outside. This company served as cover for "Sherut Avir" of the Haganah.