Harold Irwin Kaplan (October 1, 1927 - January 15, 1998) was a psychiatrist and founding editor of the Comprehensive Textbook of Psychiatry.
Kaplan received his BA degree from New York University.
In 1949, at age 21, he received his Doctorate in Medicine from New York Medical College.
During his medical career, Kaplan was Professor of Psychiatry at the NYU School of Medicine.
From 1953 to 1968 he was married to sex therapist Helen Singer Kaplan.