Paul Weiss grew up on the Lower East Side of New York City. His father, Samuel Weiss (d. 1917), was a Hungarian emigrant who moved from Europe in the 1890s. He worked as a tinsmith, a coppersmith, and a boilermaker. Paul Weiss's mother, Emma Rothschild (Weiss) (d. 1915), was a German emigrant who worked as a servant until she married Samuel. Born into a Jewish family, Paul lived among other Jewish families in a working-class neighborhood in the Yorkville section of Manhattan. Originally given the Hebrew name "Peretz," Weiss says in his autobiography that the name "Paul" was his "registered name" and "part of his mother's attempt to move upward in the American world." He had three brothers, two older and one younger.