Rabbi Yitzchak Elchanan Spektor was born in 1817 in Ros, Grodno province, the son of Rabbi Israel Isser, the town's rabbi and moreh tzedek, who was his first teacher. Married at thirteen, he settled with his in-laws in Volkovisk, where he studied under the town's rabbi, Rabbi Binyamin Diskin, and for a time under Rabbi Eliyahu Schick; there he befriended his teacher's son, the future Maharil Diskin. He was ordained by Rabbi Binyamin Diskin and by Rabbi Yitzchak Eizik Chaver of Tiktin.

In 1837, before he was twenty, he became rabbi of Zabelin, then of Berezo (1839), Nesvizh (1846) and Novardok (1851-1864), before being appointed rabbi of Kovno (Kaunas), where he remained until his death. He was called "the Rav of all Israel" (Rashkabag).

The supreme halachic authority of his generation, he received questions from all over the world; his responsa, collected in Be'er Yitzchak, Ein Yitzchak and Nachal Yitzchak, are standard references. He was also known for his great kindness and concern for the most vulnerable, especially agunot, women whose husbands had disappeared, a field in which he was the leading authority. He also defended Russia's Jewish communities before the authorities. The rabbinical school of Yeshiva University in New York (RIETS) bears his name.

He passed away in Kovno on 21 Adar 5656 (1896).