He made his stage debut with the high school's dramatic society, as the juvenile in Augustin MacHugh's The Meanest Man in the World.
Encouraged by some of his teachers, he began to turn his attention to acting. ĭismissed from Polytechnic Prep School, he finished his secondary education at Brooklyn Manual Training High School which he described as "an ordinary high school that had an awful lot of shop." He was a co-editor of the school magazine and yearbook, and he envisioned a career in writing, though he later came to realize that writing was, for him, "absolutely the most painful thing in the world" and also that he "could never meet a deadline", whereas he found the reading aloud of plays easy and enjoyable. He attended public and private schools in Brooklyn, spending summer vacations in New Jersey, Upstate New York, and at a cousin's home in Massachusetts.
Reared in Brooklyn, Scourby was a member of a Boy Scout troop and later became a cadet with the 101st National Guard Cavalry Regiment.
Alexander Scourby was born in Brooklyn, New York, on November 13, 1913, to Constantine Nicholas Scourby, a successful restaurateur, wholesale baker and sometime investor in independent motion-pictures, and Betsy Patsakos, a homemaker, both of whom were immigrants from Greece.