Avraham Abba Leifer (1918 – 7 January 1990) was the second Rebbe of the PittsburgHasidic dynasty and the instigator for the relocation of the Hasidut from its original location in Pittsburgh, Pennsylvania to the Israeli coastal city of Ashdod. He was widely known for his yiras Shamayim (fear of Heaven), humility and friendliness toward Jews of all backgrounds.
Avraham Abba Leifer was born in Nagykároly, Hungary (today Carei, Romania) to Rabbi Yosef Leifer, the grandson of Rabbi Mordechai of Nadvorna and a direct descendant of Grand Rabbi Meir the Great of Premishlan, a disciple of the Baal Shem Tov. He was the oldest of four brothers; the others were Yissachar Ber, Mordechai and Yitzchak Eisik. Yitzchak Eisik died at the age of 11.
Before the First World War, Rabbi Yosef Leifer traveled to America to raise money to marry off his orphaned nieces. When he came to the city of Pittsburgh, Pennsylvania, the local Hasidic community asked him to stay and serve as their spiritual leader. Rabbi Yosef agreed and brought over his entire family, naming himself the Pittsburger Rebbe. He served as Rebbe for more than four decades, until his death on 7 March 1966 (Shushan Purim 5726).
Though the family now lived in America, the Pittsburger Rebbe sent his three eldest sons to learn in yeshivas in Europe. He sent Avraham Abba to the yeshiva in Rachov right after his bar mitzvah in 1930. Avraham Abba received rabbinic ordination there at the age of 17, being fluent in the Shulchan Aruch and knowing the entire Shas by heart. He also learned in the yeshiva in Sekelheid, considered to be the crown of Hungarian yeshivas, where he excelled in his studies.
He married Rachel Rosenbaum, the daughter of Rabbi Isamar Rosenbaum, Admor of Nadvorna. Due to the political situation in Europe, his parents were unable to attend the wedding. He and his new wife were supported by her father for eight years in the city of Chernowitz.