U. R. Ghatak was born on 26 February 1931 at Brahmanbaria, a town of historic importance in the undivided Bengal of British India (presently in Bangladesh) to Hem Ranjan Ghatak-Soudamini Devi couple as one among their seven children. He did his schooling locally and after passing matriculation examination in 1947, he completed his intermediate studies in Agartala in 1949. His graduate studies (BSc hons) were at Asutosh College in chemistry and secured his master's degree from Rajabazar Science College in 1953, winning Motilal Mullick Medal and University Gold Medal for standing first in the examination. Subsequently, he enrolled for doctoral studies at Indian Association for the Cultivation of Science (IACS) and studied under the guidance of P. C. Dutta, a synthetic organic chemist, and obtained a PhD from Rajabazar Science College, Calcutta University in 1957. He stayed with IACS for two more years before moving to the US for his post-doctoral studies at three centres viz. University of Maine, the University of California, Berkeley and St. John’s University. He returned to India to IACS in 1963 to resume his career there and worked there till his official retirement from service in 1996; in between, he served as the head of the department of organic chemistry (1977–89) and as the director (1989–96). Later, he was associated with the Indian Institute of Chemical Biology as an INSA Senior Scientist.
Ghatak was married to Anindita and the couple lived in Kolkata. It was here he died, succumbing a massive heart attack, on 18 June 2005, at the age of 76, survived by his wife.