Early life and career
Hillerman was born in
Denison, Texas, the son of Christopher Benedict Hillerman, a gas station owner, and Lenora Joan (née Medlinger).
 He was the middle child with two sisters.
 His father was the grandson of immigrants from
 and his mother the daughter of immigrants from
Austria and Germany.
 Hillerman developed an interest in
opera at the age of ten, and traveled to
Dallas to watch
Metropolitan Opera productions.
 He attended St. Xavier's Academy,
 and after graduation, he attended the
University of Texas at Austin for three years, majoring in
Hillerman served four years in the
United States Air Force (1953-1957), working in maintenance in a
B-36 wing of the
Strategic Air Command, and achieving the rank of
 He became interested in acting after working with a
theatrical group in
Fort Worth during his service: "I was bored with barracks life. I got into [acting] to meet people in town. A light went on."
 After his 1957 discharge, he moved to
New York City to study at the
American Theatre Wing, and performed in professional theater for the next twelve years, in productions such as
Henry IV, Part 2 and
The Great God Brown.
 Despite over 100 stage roles,
 Hillerman was unable to make a living as a stage actor, and he moved to
Hollywood in 1969.