Nachman of Breslov (Hebrew: רַבִּי נַחְמָן מִבְּרֶסְלֶב Rabbī Naḥmān mīBreslev), also known as Rabbi Nachman of Breslev, Rabbi Nachman miBreslev, Reb Nachman of Bratslav, Reb Nachman Breslover (Yiddish: רבי נחמן ברעסלאווער Rebe Nakhmen Breslover), and Nachman from Uman (April 4, 1772 – October 16, 1810), was the founder of the Breslov Hasidic movement. He was particularly known for his creative parables, drawing on Eastern European folktales to infuse his teaching with deeply kabbalistic yet universally accessible remedies, pieces of advice, and parabolic stories. He emphasized finding and expressing one’s uniqueness while steering away from despair in a world he saw as becoming more and more uniform. Through Martin Buber's translation, his teaching is thought to have influenced some 20th-century writers, including Franz Kafka.

Rabbi Nachman, a great-grandson of the Baal Shem Tov, revived the Hasidic movement by combining the Kabbalah with in-depth Torah scholarship. He attracted thousands of followers during his lifetime, and his influence continues today in Breslover Hasidism and non-Hasidic movements. Rabbi Nachman's religious philosophy revolved around closeness to God, speaking to God in normal conversation "as you would with a best friend", and being happy. The concept of hitbodedut was central to his thinking.

Rabbi Nahman was born the 1st of Nisan and his day of passing (Yortzeit/Hilula) is on the 18th of Tishrei.

Nachman was born on April 4, 1772 (Rosh Chodesh Nisan), into a family of central figures in Hasidism in the town then known as Międzybóż in the Polish–Lithuanian Commonwealth, now Medzhybizh, Ukraine. Initially, he declined to take on his family's tradition of leading Hasidism.

Nachman's mother, Feiga, was the daughter of Adil (also spelled Udel), daughter of the Baal Shem Tov. His father Simcha was the son of a Baal Shem Tov disciple for whom Nachman was named: Nachman of Horodenka (Gorodenka), who was a seventh-generation lineal descendant of Judah Loew ben Bezalel. Nachman had two brothers, Yechiel Zvi and Yisroel Mes, and a sister, Perel.

At 13, he married Sashia, daughter of Rabbi Ephraim, and moved to his father-in-law's home in Ossatin. He acquired his first disciple on his wedding day—a young man named Shimon, who was several years older than him.

During 1798–1799, he traveled from Ukraine to the land of Ottoman Palestine, where he visited Hasidim living in Haifa, Tiberias, and Safed. He arrived in Galilee right before Napoleon’s battle with the Turks. This journey, which he saw as a private rite of passage, was often looked back on as a source of inspiration for him. In Tiberias, his influence brought about a reconciliation between the Lithuanian and Volhynian Hasidim. On his return from Ottoman Palestine, he was ready to assume the mantle of leadership in Hasidism, which he did in a highly selective manner. In his early years of leadership, he made each disciple confess all of his sins to him, as well as participate in a daily hour-long conversation with God.

Shortly before Rosh Hashana 1800, Nachman moved to the town of Zlatopol.