The group has invested just under £3m in the rebrands so far, with each store costing an average of £300,000.
The first two stores to be launched with the new Co-op fascia were in Tonypandy, South Wales, and New Milton in Hampshire. Each store was closed for five days while work was carried out.
The new-look stores were said to be well-recieved by the local people, with schoolchildren invited to join in the opening celebrations.
New Milton store manager Dani Ruiz-Perez said customer feedback was "extremely positive" and that many shoppers had already become Co-operative members.
Other Somerfield supermarkets refurbished and rebranded include Padiham, Lancashire; Worthing, West Sussex; and Tonyrefail and Newbridge in Wales.