Pressman was born Leon Pressman on July 1, 1906, on the Lower East Side of in New York City, first of two sons of immigrants Harry and Clara Pressman of Minsk.
His father was a milliner on the Lower East Side of New York City.
As a child, Leon survived polio.
 In his teens, the family moved out to the Bensonhurst section of Brooklyn.
In 1922, he entered Washington Square College (absorbed into New York University), where classmates included Nathan Witt and possibly Charles Kramer (later, fellow AAA and Ware Group members), then transferred to Cornell University, where he studied under labor economist Sumner Slichter.

In 1926, Pressman received his bachelor's degree from Cornell University in Ithaca, New York.
 In 1929, he received a law degree from Harvard Law School.
 At Harvard, he was a member of Phi Beta Kappa and was in the same class as Alger Hiss.
With future defending lawyer Edward Cochrane McLean, they served on the Harvard Law Review:
Mr. Hiss:  ... Lee Pressman was in my class at the Harvard Law School, and we were both on the Harvard Law Review at the same time.
Pressman was born Leon Pressman on July 1, 1906, on the Lower East Side of in New York City, first of two sons of immigrants Harry and Clara Pressman of Minsk. His father was a milliner on the Lower East Side of New York City. As a child, Leon survived polio.  In his teens, the family moved out to the Bensonhurst section of Brooklyn. In 1922, he entered Washington Square College (absorbed into New York University), where classmates included Nathan Witt and possibly Charles Kramer (later, fellow AAA and Ware Group members), then transferred to Cornell University, where he studied under labor economist Sumner Slichter.
In 1926, Pressman received his bachelor's degree from Cornell University in Ithaca, New York.  In 1929, he received a law degree from Harvard Law School.  At Harvard, he was a member of Phi Beta Kappa and was in the same class as Alger Hiss. With future defending lawyer Edward Cochrane McLean, they served on the Harvard Law Review:
Mr. Hiss:  ... Lee Pressman was in my class at the Harvard Law School, and we were both on the Harvard Law Review at the same time.
Lee Pressman