The elder of two sons of Gurdial Kaur Oppal, Oppal was born in Vancouver to Sikh immigrant parents from India.[2] The whole family moved to the Lake Cowichan area after his father co-founded a sawmill with a partner there. After his father died when he was 10 years old, his mother worked as a housekeeper.[2] He attended Lake Cowichan High School where he served as student council president in his senior year, and graduated in 1958.[2][3]
After briefly working as a radio announcer, he began attending the University of British Columbia (UBC), supplementing his income by working at sawmills during the summer. He graduated with a B.A. from UBC in 1963, followed by a law degree from the UBC Faculty of Law in 1966.[2][3] He was called to the bar in 1967 and began working at Thompson McConnell, eventually starting a private practice in South Vancouver with friend John Campbell.[2][3]
At the recommendation of then-Chief Justice of the Supreme Court of British Columbia Allan McEachern, Oppal was appointed to the County Court of Vancouver in 1981, and to the BC Supreme Court in 1985. In 2003, he was appointed to the British Columbia Court of Appeal where he served until he resigned to seek election to the provincial legislature.[3] He was appointed to lead a commission of inquiry into policing in British Columbia in June 1992, and published a report in 1994, leading to policing reforms in the province.[2][4]
On May 26, 2009, a recount revealed that Huntington had defeated Oppal by only 32 votes.[11] A judicial recount on June 2 confirmed Huntington's victory.[12]
Oppal served as the Chancellor of the Thompson Rivers University in Kamloops from 2011 to 2018, and was named Chancellor Emeritus upon the end of his terms.[16][17][18] In 2019 he was appointed to chair a committee to oversee the creation of a new municipal police force in the city of Surrey, which would replace the Royal Canadian Mounted Police.[19]
Oppal is married with two children.[2][7] He announced in March 2007 that he was undergoing treatment for prostate cancer.[22] By the end of the month, Oppal was declared cancer free by his doctor.[citation needed]