Yaakov Segal was born in Jaffa. In 1906, at the age of three, he came with his family to Rishon Le Zion. He studied at the local elementary school ("Haviv") and in the "Herzlia" High School in Tel Aviv. He then studied law in Torino, Italy and in the Law School of the Mandatory government in Jerusalem. He graduated as a lawyer in 1929. When he married in 1930 he moved to Tel Aviv and worked there as an independent lawyer. Later he was appointed as chief justice in the magistrates court in Tel Aviv where he worked until he retired.
Yaakov Segal was involved in a wide range of public activities. He was involved in the Tzofim and Maccabi youth movements, acted as chairman of the Maccabi and as chairman of the High Court of the Maccabi Union in Palestine and of the World Maccabi organization. As a sportman himself he engaged in athletics and football. He was a member of the senior committee of the football league in Palestine and of its high court. In 1922 the Malabeit sports group was formed and named "Haye-elim" and Yaakov Segal was chairman of the group. He was an active member of the "Hagana". From 1941 he was a member of the "Hagana" headquarters in the Tel Aviv district. He was a committee member of the General Zionists political party in Eretz Israel and a member of its Tel Aviv branch. He was a member of "Bnei Brit" and the Freemasons and president of the Tel Aviv branch for many years. After the State was founded he acted as chairman of the Requisitioning and Compensation Committee of the Ministry of Defence. After his death, in accordance with his will, a fund was set up to help underprivileged children in Rishon Le-Zion to study in high school and in institutions of higher education. The fund has been continuously active for many years. Yaakov Segal was brought for burial in the old cemetery in Rishon Le-Zion.