Board member Melissa Vining said the Southland pair’s donation had given the cause "an enormous boost" yesterday.
"They are just beautiful people, and we cannot thank them enough.
"Their act of selflessness is literally going to save the lives of people in our community."
The couple had shown "mind-blowing" generosity, Mrs Vining said.
The large donation, and the support of "countless others", meant Southland and Otago families would not lose their husbands, fathers, mothers, children, grandmothers, she said.
The hospital development was instigated by Melissa Vining and her late husband, Blair, in September 2019. He died of bowel cancer a month later.
Mr Vining received a terminal diagnosis in 2018.
He fought for better healthcare access in the South, garnering national attention, and was the driving force in the creation of the Southland Charity Hospital Trust.
Mrs Vining said she could not "put into words how much of a difference" yesterday’s donation had made for the Southland Charity Hospital’s future.
"Every dollar we raise gets us one step closer to turning the Southland Charity Hospital into a reality.
"Every dollar we raise means we are closer to being able to help our communities."
