Rabbi Pinchas David Horowitz, (July 15, 1877^[1] or 1876 - November 28, 1941)^[2] was a Hasidic rebbe and the founder of the Boston Hasidic dynasty, one of the first Hasidic courts in America.

Born in Jerusalem, he was a paternal descendant of Zevi Joshua Horowitz, son of Shmelke Horowitz of Nikolsburg. He was sent as a representative and arbitrator by the Jerusalem community to Russia in an important European rabbinic dispute.^{[citation needed]} The outbreak of World War I prevented his return to Palestine and in 1915 he went to Boston to collect money for charity (tzedakah). He attracted a small group of followers but soon left Boston for New York.^[3] In 1939 Rabbi Pinchas Horowitz relocated the congregation to the Williamsburg section of Brooklyn, remaining there until his death on November 28, 1941.^[3]

Horowitz's successors were his sons, rabbis Moshe Horowitz, the Bostoner Rebbe of New York, and Levi Yitzchok Horowitz, the Bostoner Rebbe of Boston and Har Nof, Jerusalem.^[2]