Cook's Dairy, the leading milk brand in Southwestern Nova Scotia supplying Shelburne, Yarmouth and Digby counties, has been owned by the Cook family for the last 85 years.
"We have been thinking about the future of Cook's Dairy for a long time and now is the time to sell our dairy," Don Cook said in a statement.
Cook's produces 2.7 million litres of milk a year. Longueuil-based Argopur produces 3.1 billion litres at 27 plants.
The purchase price was not disclosed.
In a release issued Thursday, Agropur said Don and Randy Cook will remain at the dairy.
"We are truly humbled by the strong support our customers have shown us over the years, making Cook's Dairy a household name in Southwest Nova Scotia," said Cook.
The farm employs 32 people directly and services 200 retailers.
Agropur recently completed the purchase of Halifax-based Farmer's Dairy.
Nova Scotia's remaining independent dairy plant is Scotsburn.