B.C. NDP MP Frank Valeriote, 87, died Tuesday morning at the B.A. Medical Centre in Vancouver.
The former cabinet minister and his wife of 45 years had been battling lung cancer for about three years.
He was also a member of the Bayshore NDP, the governing party in the province.
Valeriot was the second former premier to die in a week, and the third to lose his health in a month.
In late April, former Liberal MP David Krashen was diagnosed with pancreatic cancer.
The Liberal Party had also announced the death of former premier Adrian Dix.
Former premier Greg Selinger died last week at age 78.
The B.K. Liberal Party said it was mourning the loss of its former leader, who led the party through the 2010 election campaign.
The party called his death a “tragic and shocking end.”
Selinger, who had been premier for 23 years, was also the longest-serving member of his party.
He lost his job in February 2016, but returned in 2017.
He resigned his seat in the legislature earlier this month to focus on his family and children.
The NDP is the only party in British Columbia that has a sitting premier.