Yaakov Homa was born in Kaunas, Lithuania. The years of his youth he spent at his grandfather's, Rabbi Avraham Abba Werner, in England. Throughout World War I, during his studies at the Sorbonne in Paris, he joined the British Army and asked to serve in the Middle East. Considerable time of his service as an intelligence officer he did at General Allenby's headquarters in Cairo. Along with Allenby's forces he came to Eretz Israel.
At the end of the war, he remained in Eretz Israel and served in senior positions in the Mandatory government.
He was in charge of Absentees Property (including assets of foreign countries) and later, served as comptroller - a position corresponding to the position of the State Comptroller.