Rabbi Chaim Zanvil Abramowitz (1902, Botoşani - October 18, 1995), known as the Ribnitzer (ריבניץ) Rebbe, was considered a great Hasidic tzadik and miracle worker from Rybnitsa (now in Transnistria, Moldova).
Abramowitz was a prominent follower of Rabbi Avrohom Matisyohu of Shtefanesht.
He lived in the USSR under Stalin's rule, yet lived a fully Jewish religious life. He served as mohel and shochet.
He fasted very often, and immersed himself many times daily in water that was sometimes only accessible by chopping away very thick ice. His Tikkun Chatzos (midnight prayer service) in sackcloth and ashes regularly lasted 6–7 hours, sometimes stretching as long as 12. He cried so much during Tikkun Chatzos that when he was done, the tears and ashes mingled so that he was sitting in mud.
The Russian gentiles feared and revered him. The KGB brought their wives and children for blessings and experienced miracles.
He left Russia in 1970 and moved to the Mattersdorf section of Jerusalem, where he lived for a few years before moving to the United States. He lived in Miami, Los Angeles, Boro Park, Seagate, Brooklyn, and finally settled in Monsey, New York.
Abramowitz died on Isru Chag Succos, 1995, in Monsey, New York. He is buried in the Vizhnitzer Cemetery.