Born in Orsha, Russian Empire in 1894, Hoz immigrated to Ottoman Palestine as a child 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 Meirov-Avigur, 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 Aviron co-founder Yitzhak Ben-Ya'akov.
Hoz and Yitzhak Ben Ya'akov from Degania Alef were the founders of Aviron Aviation Company, for which Hoz acted as CEO. Aviron was one of a handful of aviation pioneering enterprises of the Yishuv, created with its foreseeable security needs in mind. It trained pilots and established flight lines in Mandatory Palestine and outside, while serving as cover for the budding, tiny and illegal "air force" of the Yishuv, eventually organised between 1945 and 10 November 1947 as Palmach's Palavir, and then until Independence as the Haganah's Sherut Avir.