Om Puri was born in Ambala. His father, Rajesh Puri, worked on the railways and in the Indian Army. As he had no birth certificate or records, his family was unsure of his date and year of birth, however, his mother told him he had been born two days after the Hindu festival Dussehra. When he began his schooling, his uncle chose 9 March 1950 as his "official" birthday, however as an adult when he moved to Mumbai, Puri looked up when Dussehra was celebrated in 1950, to establish his date of birth as 18 October.