The province says the oral medication Kalydeco will be covered starting Monday.
The drug can be expensive with costs running to $300,000 a year for one patient.
Drug-maker Vertex Pharmaceuticals reached an agreement with the provincial and territorial governments in June to enable public drug plans to cover the medication's cost.
Negotiations had been going on for more than a year.
It's believed to be the first drug that corrects the faulty mechanism that causes cystic fibrosis in the first place.
The drug only works for a small subset of patients whose disease is caused by a mutation on the specific gene.