Harry A. B. Shapiro was born in the Russian Empire in what is now Lithuania, likely in or near the city of Alytus. A passenger manifest lists his given name as Hirsch Shapiro and his father's naturalization papers list his birth date as May 1, 1904. His father Israel immigrated to the United States shortly after Harry’s birth, working as a dry goods peddler, furniture maker, and upholsterer. Harry immigrated with his mother Rose, older brother Khaim Leib, and older sister Rena in 1907. The family were passengers on the steerage deck of The Celtic, a White Star Line ocean liner. Leib became ill during the voyage and died a short time later. The family landed in New York with just $2 in declared cash.
Though imigration documents indicate that the family's destination was Auburn, Maine, the Shapiros ultimately settled in Malden, Massachusetts in an area that included a number of other Lithuanian immigrants. Harry’s younger sister Helen and brother Eugene were born in Malden. The family was Jewish and Yiddish was the language spoken in the home. Harry attended High School in Malden, graduating in 1923 with a commercial focus. His yearbook quote reads “If success won’t come to Shap, we know Shap will go right out and get it.”
Harry studied for his Bachelor of Business Administration degree at Boston University’s College of Business Administration. He graduated with honors in 1927. He worked his way through school, obtaining accounting related jobs through his instructors. While at B.U. Harry was a member of the Menorah Society (a Jewish cultural organization), El Centro Español (the Spanish language club), and maintained an interest in collecting stamps. One of Harry’s proudest moments as a student came when he was asked to proofread and critique a textbook, Mathematics of Finance and Accounting, written by Professor James V. Toner.