Botterills has been trading for more than 50 years, operating stores under the Spar franchise. It employs about 1,000 people.
The acquisition will boost Scotmid's store estate to just under 200 stores throughout Scotland, stretching from north of Inverness to Dumfries in the south. It is anticipated that stores will be rebranded to Scotmid Co-operative in the next few years.
Scotmid Co-operative chief executive John Brodie said the move was in line with its strategy to "become Scotland's preferred community convenience retailer".
He added: "I would like to give special mention to Jim Botterill and his family for the professional way they have conducted negotiations, especially as they were selling a family business that has meant so much to them."
Jim Botterill said that concluding the sale process was "difficult and emotional". He added: "However, we had to look to the future and see how best we could look after our staff and customers."