| John Isaiah Northrop | |
| Birth Date: | October 12, 1861 |
| Birth Place: | New York City, United States |
| Death Date: | June 27, 1891 |
| Death Place: | New York City |
| Occupation: | Zoologist |
| Spouse: | Alice Belle Rich |
| Parents: | John Isaiah Northrop and Mary Rosina Havemeyer |
| Relatives: | See Havemeyer family |
John Isaiah Northrop, Ph.D. (12 October 1861 – 27 June 1891) was an American zoologist at Columbia University.
John I. Northrop was born in New York City. He was named after his father, John Isaiah Northrop, a pharmacist. His mother, Mary R. Havemeyer, was a sister of Frederic Christian Havemeyer, a graduate of Columbia College, after whom Havemeyer Hall is named. His father died when he was two years old. Northrop studied for some years at a private school in New Windsor, New York, then at the Columbia Grammar & Preparatory School, in which he prepared for the Columbia School of Mines. He graduated in 1884, with the degree of Engineer of Mines.[1]
On June 28, 1889, he married Alice Belle Rich,[2] at the time professor in Botany at the Hunter College. In 1891, almost exactly two years after his marriage, Dr. Northrop was killed in a laboratory explosion at the Columbia School of Mines. His only child, John Howard Northrop (Nobel Laureate in Chemistry, 1946), was born nine days after his father's death.[3]