Harold I. Kaplan (1928– January 15, 1998) was a Canadian-American psychiatrist and founding editor of the Comprehensive Textbook of Psychiatry. From 1953 to 1968 he was married to sex therapist Helen Singer Kaplan. He was also married to Nancy Barrett.
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. He was also an Attending Psychiatrist at Bellevue Hospital, Lenox Hill Hospital, and NYU Langone Medical Center.
Kaplan was a Life Fellow of the American Psychiatric Association, the American College of Physicians, and the New York Academy of Medicine. He helped found the NYU-Bellevue Psychiatric Association of New York.
Kaplan died on January 15, 1998.